Vulnerability-Lookup

CVE-2018-20021 (GCVE-0-2018-20021)

Vulnerability from cvelistv5 – Published: 2018-12-19 16:00 – Updated: 2024-08-05 11:51

Summary

LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM

Severity

7.5 (High)


                        
                          CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

Denial of Service

Assigner

Kaspersky mitre root

References

12 references

URL	Tags
https://www.debian.org/security/2019/dsa-4383	vendor-advisoryx_refsource_DEBIAN
https://lists.debian.org/debian-lts-announce/2018…	mailing-listx_refsource_MLIST
https://ics-cert.kaspersky.com/advisories/klcert-…	x_refsource_MISC
https://usn.ubuntu.com/3877-1/	vendor-advisoryx_refsource_UBUNTU
https://security.gentoo.org/glsa/201908-05	vendor-advisoryx_refsource_GENTOO
https://lists.debian.org/debian-lts-announce/2019…	mailing-listx_refsource_MLIST
https://lists.debian.org/debian-lts-announce/2019…	mailing-listx_refsource_MLIST
https://lists.debian.org/debian-lts-announce/2019…	mailing-listx_refsource_MLIST
https://security.gentoo.org/glsa/202006-06	vendor-advisoryx_refsource_GENTOO
https://usn.ubuntu.com/4547-1/	vendor-advisoryx_refsource_UBUNTU
https://usn.ubuntu.com/4547-2/	vendor-advisoryx_refsource_UBUNTU
https://usn.ubuntu.com/4587-1/	vendor-advisoryx_refsource_UBUNTU

Impacted products

1 product

Vendor	Product	Version	CPE status
n/a	LibVNC	Affected: commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c

Date Public

2018-12-19 00:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-05T11:51:18.342Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "DSA-4383",
            "tags": [
              "vendor-advisory",
              "x_refsource_DEBIAN",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2019/dsa-4383"
          },
          {
            "name": "[debian-lts-announce] 20181227 [SECURITY] [DLA 1617-1] libvncserver security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
          },
          {
            "name": "USN-3877-1",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/3877-1/"
          },
          {
            "name": "GLSA-201908-05",
            "tags": [
              "vendor-advisory",
              "x_refsource_GENTOO",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/201908-05"
          },
          {
            "name": "[debian-lts-announce] 20191030 [SECURITY] [DLA 1979-1] italc security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
          },
          {
            "name": "[debian-lts-announce] 20191129 [SECURITY] [DLA 2016-1] ssvnc security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
          },
          {
            "name": "[debian-lts-announce] 20191221 [SECURITY] [DLA 2045-1] tightvnc security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
          },
          {
            "name": "GLSA-202006-06",
            "tags": [
              "vendor-advisory",
              "x_refsource_GENTOO",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202006-06"
          },
          {
            "name": "USN-4547-1",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4547-1/"
          },
          {
            "name": "USN-4547-2",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4547-2/"
          },
          {
            "name": "USN-4587-1",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4587-1/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "LibVNC",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c"
            }
          ]
        }
      ],
      "datePublic": "2018-12-19T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Denial of Service",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2020-10-23T12:06:31.000Z",
        "orgId": "e45d732a-8f6b-4b6b-be76-7420f6a2b988",
        "shortName": "Kaspersky"
      },
      "references": [
        {
          "name": "DSA-4383",
          "tags": [
            "vendor-advisory",
            "x_refsource_DEBIAN"
          ],
          "url": "https://www.debian.org/security/2019/dsa-4383"
        },
        {
          "name": "[debian-lts-announce] 20181227 [SECURITY] [DLA 1617-1] libvncserver security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
        },
        {
          "name": "USN-3877-1",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/3877-1/"
        },
        {
          "name": "GLSA-201908-05",
          "tags": [
            "vendor-advisory",
            "x_refsource_GENTOO"
          ],
          "url": "https://security.gentoo.org/glsa/201908-05"
        },
        {
          "name": "[debian-lts-announce] 20191030 [SECURITY] [DLA 1979-1] italc security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
        },
        {
          "name": "[debian-lts-announce] 20191129 [SECURITY] [DLA 2016-1] ssvnc security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
        },
        {
          "name": "[debian-lts-announce] 20191221 [SECURITY] [DLA 2045-1] tightvnc security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
        },
        {
          "name": "GLSA-202006-06",
          "tags": [
            "vendor-advisory",
            "x_refsource_GENTOO"
          ],
          "url": "https://security.gentoo.org/glsa/202006-06"
        },
        {
          "name": "USN-4547-1",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4547-1/"
        },
        {
          "name": "USN-4547-2",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4547-2/"
        },
        {
          "name": "USN-4587-1",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4587-1/"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "vulnerability@kaspersky.com",
          "ID": "CVE-2018-20021",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "LibVNC",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM"
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "Denial of Service"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "DSA-4383",
              "refsource": "DEBIAN",
              "url": "https://www.debian.org/security/2019/dsa-4383"
            },
            {
              "name": "[debian-lts-announce] 20181227 [SECURITY] [DLA 1617-1] libvncserver security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
            },
            {
              "name": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/",
              "refsource": "MISC",
              "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
            },
            {
              "name": "USN-3877-1",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/3877-1/"
            },
            {
              "name": "GLSA-201908-05",
              "refsource": "GENTOO",
              "url": "https://security.gentoo.org/glsa/201908-05"
            },
            {
              "name": "[debian-lts-announce] 20191030 [SECURITY] [DLA 1979-1] italc security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
            },
            {
              "name": "[debian-lts-announce] 20191129 [SECURITY] [DLA 2016-1] ssvnc security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
            },
            {
              "name": "[debian-lts-announce] 20191221 [SECURITY] [DLA 2045-1] tightvnc security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
            },
            {
              "name": "GLSA-202006-06",
              "refsource": "GENTOO",
              "url": "https://security.gentoo.org/glsa/202006-06"
            },
            {
              "name": "USN-4547-1",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4547-1/"
            },
            {
              "name": "USN-4547-2",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4547-2/"
            },
            {
              "name": "USN-4587-1",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4587-1/"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "e45d732a-8f6b-4b6b-be76-7420f6a2b988",
    "assignerShortName": "Kaspersky",
    "cveId": "CVE-2018-20021",
    "datePublished": "2018-12-19T16:00:00.000Z",
    "dateReserved": "2018-12-10T00:00:00.000Z",
    "dateUpdated": "2024-08-05T11:51:18.342Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2018-20021",
      "date": "2026-09-19",
      "epss": "0.03515",
      "percentile": "0.88682"
    },
    "fkie_nvd": {
      "configurations": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:*",
                  "matchCriteriaId": "DEF1BF44-78B8-44E3-9A5A-29AB8111322B",
                  "versionEndExcluding": "0.9.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        },
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*",
                  "matchCriteriaId": "B5A6F2F3-4894-4392-8296-3B8DD2679084",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
                  "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                  "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*",
                  "matchCriteriaId": "07C312A0-CD2C-4B9C-B064-6409B25C278F",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*",
                  "matchCriteriaId": "C11E6FB0-C8C0-4527-9AA0-CB9B316F8F43",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                  "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM"
        },
        {
          "lang": "es",
          "value": "LibVNC antes del commit con ID c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contiene una vulnerabilidad CWE-835: bucle infinito en el c\u00f3digo del cliente VNC. Esta vulnerabilidad permite que el atacante consuma una cantidad excesiva de recursos como la CPU y la RAM."
        }
      ],
      "id": "CVE-2018-20021",
      "lastModified": "2024-11-21T04:00:46.313",
      "metrics": {
        "cvssMetricV2": [
          {
            "acInsufInfo": false,
            "baseSeverity": "HIGH",
            "cvssData": {
              "accessComplexity": "LOW",
              "accessVector": "NETWORK",
              "authentication": "NONE",
              "availabilityImpact": "COMPLETE",
              "baseScore": 7.8,
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:C",
              "version": "2.0"
            },
            "exploitabilityScore": 10.0,
            "impactScore": 6.9,
            "obtainAllPrivilege": false,
            "obtainOtherPrivilege": false,
            "obtainUserPrivilege": false,
            "source": "nvd@nist.gov",
            "type": "Primary",
            "userInteractionRequired": false
          }
        ],
        "cvssMetricV30": [
          {
            "cvssData": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.0"
            },
            "exploitabilityScore": 3.9,
            "impactScore": 3.6,
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      },
      "published": "2018-12-19T16:29:00.420",
      "references": [
        {
          "source": "vulnerability@kaspersky.com",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://security.gentoo.org/glsa/201908-05"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://security.gentoo.org/glsa/202006-06"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://usn.ubuntu.com/3877-1/"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://usn.ubuntu.com/4547-1/"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://usn.ubuntu.com/4547-2/"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "url": "https://usn.ubuntu.com/4587-1/"
        },
        {
          "source": "vulnerability@kaspersky.com",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://www.debian.org/security/2019/dsa-4383"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://security.gentoo.org/glsa/201908-05"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://security.gentoo.org/glsa/202006-06"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://usn.ubuntu.com/3877-1/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://usn.ubuntu.com/4547-1/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://usn.ubuntu.com/4547-2/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://usn.ubuntu.com/4587-1/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://www.debian.org/security/2019/dsa-4383"
        }
      ],
      "sourceIdentifier": "vulnerability@kaspersky.com",
      "vulnStatus": "Modified",
      "weaknesses": [
        {
          "description": [
            {
              "lang": "en",
              "value": "CWE-835"
            }
          ],
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ]
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "DEF1BF44-78B8-44E3-9A5A-29AB8111322B",
                    "versionEndExcluding": "0.9.12",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "B5A6F2F3-4894-4392-8296-3B8DD2679084",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*",
                    "matchCriteriaId": "07C312A0-CD2C-4B9C-B064-6409B25C278F",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "C11E6FB0-C8C0-4527-9AA0-CB9B316F8F43",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM"
          },
          {
            "lang": "es",
            "value": "LibVNC antes del commit con ID c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contiene una vulnerabilidad CWE-835: bucle infinito en el c\u00f3digo del cliente VNC. Esta vulnerabilidad permite que el atacante consuma una cantidad excesiva de recursos como la CPU y la RAM."
          }
        ],
        "id": "CVE-2018-20021",
        "lastModified": "2024-11-21T04:00:46.313",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "HIGH",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "COMPLETE",
                "baseScore": 7.8,
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:C",
                "version": "2.0"
              },
              "exploitabilityScore": 10.0,
              "impactScore": 6.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV30": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.0"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2018-12-19T16:29:00.420",
        "references": [
          {
            "source": "vulnerability@kaspersky.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://security.gentoo.org/glsa/201908-05"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://security.gentoo.org/glsa/202006-06"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/3877-1/"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://usn.ubuntu.com/4547-1/"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://usn.ubuntu.com/4547-2/"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "url": "https://usn.ubuntu.com/4587-1/"
          },
          {
            "source": "vulnerability@kaspersky.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2019/dsa-4383"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2019/11/msg00033.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00028.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://security.gentoo.org/glsa/201908-05"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://security.gentoo.org/glsa/202006-06"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/3877-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://usn.ubuntu.com/4547-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://usn.ubuntu.com/4547-2/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://usn.ubuntu.com/4587-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2019/dsa-4383"
          }
        ],
        "sourceIdentifier": "vulnerability@kaspersky.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-835"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2025-11-21T16:46:13+00:00",
      "cve": "CVE-2018-20021",
      "id": "CVE-2018-20021",
      "initial_release_date": "2018-12-19T00:00:00+00:00",
      "product_status:known_affected": "3",
      "product_status:known_not_affected": "6",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "libvncserver: Infinite loop in VNC client code allows for denial of service",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2018/cve-2018-20021.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-09T00:42:37Z",
      "cve": "CVE-2018-20021",
      "id": "CVE-2018-20021",
      "initial_release_date": "2023-02-15T04:21:31Z",
      "product_status:known_affected": "44",
      "product_status:recommended": "131",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2018-20021",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2018-20021.json",
      "version": "22"
    }
  }
}

SUSE-SU-2019:13927-1

Vulnerability from csaf_suse - Published: 2019-01-11 08:42 - Updated: 2019-01-11 08:42

Summary

Security update for LibVNCServer

Severity

Important

Scope

8 vulnerabilities in this advisory, including CVE-2018-20021.

CVE-2018-20021

6.5 (Medium)


                
                  CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Recommended: 22 products

Open the full advisory

UBUNTU-CVE-2018-20021 (CVE-2018-20021)

Vulnerability from osv_ubuntu – Published: 2018-12-19 00:00 – Updated: 2026-05-20 14:50 – Source website

Details

Severity

7.5 (High)


                    
                      CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2018-20021	REPORT
	https://ics-cert.kaspersky.com/advisories/klcert-…	REPORT
	https://ubuntu.com/security/notices/USN-3877-1	ADVISORY
	https://ubuntu.com/security/notices/USN-4547-1	ADVISORY
	https://ubuntu.com/security/notices/USN-4547-2	ADVISORY
	https://ubuntu.com/security/notices/USN-4587-1	ADVISORY
	https://www.cve.org/CVERecord?id=CVE-2018-20021	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libvncserver-config",
            "binary_version": "0.9.9+dfsg-1ubuntu1.4"
          },
          {
            "binary_name": "libvncserver0",
            "binary_version": "0.9.9+dfsg-1ubuntu1.4"
          },
          {
            "binary_name": "linuxvnc",
            "binary_version": "0.9.9+dfsg-1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:14.04:LTS",
        "name": "libvncserver",
        "purl": "pkg:deb/ubuntu/libvncserver@0.9.9+dfsg-1ubuntu1.4?arch=source\u0026distro=trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.9+dfsg-1ubuntu1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.9+dfsg-1",
        "0.9.9+dfsg-1ubuntu1",
        "0.9.9+dfsg-1ubuntu1.1",
        "0.9.9+dfsg-1ubuntu1.2",
        "0.9.9+dfsg-1ubuntu1.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "tightvncserver",
            "binary_version": "1.3.9-6.5+deb8u1build0.14.04.1~esm1"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1.3.9-6.5+deb8u1build0.14.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1.3.9-6.5+deb8u1build0.14.04.1~esm1?arch=source\u0026distro=trusty/esm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.3.9-6.5+deb8u1build0.14.04.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.9-6.4",
        "1.3.9-6.4ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "italc-client",
            "binary_version": "1:2.0.2+dfsg1-4ubuntu0.1"
          },
          {
            "binary_name": "italc-management-console",
            "binary_version": "1:2.0.2+dfsg1-4ubuntu0.1"
          },
          {
            "binary_name": "italc-master",
            "binary_version": "1:2.0.2+dfsg1-4ubuntu0.1"
          },
          {
            "binary_name": "libitalccore",
            "binary_version": "1:2.0.2+dfsg1-4ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "italc",
        "purl": "pkg:deb/ubuntu/italc@1:2.0.2+dfsg1-4ubuntu0.1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:2.0.2+dfsg1-4ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:2.0.2+dfsg1-3",
        "1:2.0.2+dfsg1-4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.10+dfsg-3ubuntu0.16.04.3"
          },
          {
            "binary_name": "libvncserver-config",
            "binary_version": "0.9.10+dfsg-3ubuntu0.16.04.3"
          },
          {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.10+dfsg-3ubuntu0.16.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "libvncserver",
        "purl": "pkg:deb/ubuntu/libvncserver@0.9.10+dfsg-3ubuntu0.16.04.3?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.10+dfsg-3ubuntu0.16.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.10+dfsg-3",
        "0.9.10+dfsg-3build1",
        "0.9.10+dfsg-3ubuntu0.16.04.1",
        "0.9.10+dfsg-3ubuntu0.16.04.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "ssvnc",
            "binary_version": "1.0.29-2+deb8u1build0.16.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "ssvnc",
        "purl": "pkg:deb/ubuntu/ssvnc@1.0.29-2+deb8u1build0.16.04.1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.29-2+deb8u1build0.16.04.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.29-2build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncserver",
            "binary_version": "1.3.10-0ubuntu3"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1.3.10-0ubuntu3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1.3.10-0ubuntu3?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.10-0ubuntu2",
        "1.3.10-0ubuntu3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "italc-client",
            "binary_version": "1:3.0.3+dfsg1-3ubuntu0.1"
          },
          {
            "binary_name": "italc-management-console",
            "binary_version": "1:3.0.3+dfsg1-3ubuntu0.1"
          },
          {
            "binary_name": "italc-master",
            "binary_version": "1:3.0.3+dfsg1-3ubuntu0.1"
          },
          {
            "binary_name": "libitalccore",
            "binary_version": "1:3.0.3+dfsg1-3ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "italc",
        "purl": "pkg:deb/ubuntu/italc@1:3.0.3+dfsg1-3ubuntu0.1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:3.0.3+dfsg1-3ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:3.0.3+dfsg1-1",
        "1:3.0.3+dfsg1-2",
        "1:3.0.3+dfsg1-2build1",
        "1:3.0.3+dfsg1-2ubuntu1",
        "1:3.0.3+dfsg1-3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.11+dfsg-1ubuntu1.1"
          },
          {
            "binary_name": "libvncserver-config",
            "binary_version": "0.9.11+dfsg-1ubuntu1.1"
          },
          {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.11+dfsg-1ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libvncserver",
        "purl": "pkg:deb/ubuntu/libvncserver@0.9.11+dfsg-1ubuntu1.1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.11+dfsg-1ubuntu1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.11+dfsg-1",
        "0.9.11+dfsg-1ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ssvnc",
            "binary_version": "1.0.29-3build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "ssvnc",
        "purl": "pkg:deb/ubuntu/ssvnc@1.0.29-3build1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.29-3",
        "1.0.29-3build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncserver",
            "binary_version": "1.3.10-0ubuntu4"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1.3.10-0ubuntu4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1.3.10-0ubuntu4?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.10-0ubuntu3",
        "1.3.10-0ubuntu4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncserver",
            "binary_version": "1.3.10-0ubuntu5"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1.3.10-0ubuntu5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1.3.10-0ubuntu5?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.10-0ubuntu5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncpasswd",
            "binary_version": "1:1.3.10-5"
          },
          {
            "binary_name": "tightvncserver",
            "binary_version": "1:1.3.10-5"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1:1.3.10-5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1:1.3.10-5?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:1.3.10-3",
        "1:1.3.10-5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncpasswd",
            "binary_version": "1:1.3.10-8"
          },
          {
            "binary_name": "tightvncserver",
            "binary_version": "1:1.3.10-8"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1:1.3.10-8"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1:1.3.10-8?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:1.3.10-7",
        "1:1.3.10-7build1",
        "1:1.3.10-7build2",
        "1:1.3.10-8"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncpasswd",
            "binary_version": "1:1.3.10-10"
          },
          {
            "binary_name": "tightvncserver",
            "binary_version": "1:1.3.10-10"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1:1.3.10-10"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1:1.3.10-10?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:1.3.10-9",
        "1:1.3.10-10"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "tightvncpasswd",
            "binary_version": "1:1.3.10-10build1"
          },
          {
            "binary_name": "tightvncserver",
            "binary_version": "1:1.3.10-10build1"
          },
          {
            "binary_name": "xtightvncviewer",
            "binary_version": "1:1.3.10-10build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "tightvnc",
        "purl": "pkg:deb/ubuntu/tightvnc@1:1.3.10-10build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:1.3.10-10",
        "1:1.3.10-10build1"
      ]
    }
  ],
  "aliases": [],
  "details": "LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM",
  "id": "UBUNTU-CVE-2018-20021",
  "modified": "2026-05-20T14:50:57Z",
  "published": "2018-12-19T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2018-20021"
    },
    {
      "type": "REPORT",
      "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-3877-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4547-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4547-2"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4587-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2018-20021"
    }
  ],
  "related": [
    "USN-3877-1",
    "USN-4547-1",
    "USN-4547-2",
    "USN-4587-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2018-20021"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2018-20021 (GCVE-0-2018-20021)

SUSE-SU-2019:13927-1

UBUNTU-CVE-2018-20021 (CVE-2018-20021)

Tags

Sightings

Nomenclature

Related by attack behaviour