fkie_cve-2021-41115
Vulnerability from fkie_nvd
Published
2021-10-07 23:15
Modified
2024-11-21 06:25
Severity ?
4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure "linkifiers" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository).
References
security-advisories@github.comhttps://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781Patch, Third Party Advisory
security-advisories@github.comhttps://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jgPatch, Third Party Advisory
security-advisories@github.comhttps://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jgPatch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/Exploit, Third Party Advisory
Impacted products
Vendor Product Version
zulip zulip *


To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:zulip:zulip:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C12C5D8B-FC65-4A14-B843-106963C0AEA8",
              "versionEndExcluding": "4.7",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure \"linkifiers\" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)."
    },
    {
      "lang": "es",
      "value": "Zulip es un servidor de chat de equipo de c\u00f3digo abierto. En las versiones afectadas, Zulip permite a los administradores de la organizaci\u00f3n en un servidor configurar \"linkifiers\" que crean autom\u00e1ticamente enlaces a partir de los mensajes que env\u00edan los usuarios, detectados por medio de expresiones regulares arbitrarias. Los administradores de organizaciones maliciosos pod\u00edan someter al servidor a una denegaci\u00f3n de servicio por medio de ataques de complejidad de expresiones regulares; m\u00e1s sencillo, al configurar una expresi\u00f3n regular de tiempo cuadr\u00e1tico en un enlazador, y enviando mensajes que la explotaran. Una expresi\u00f3n regular intentaba analizar las expresiones regulares proporcionadas por el usuario para verificar que estaban a salvo de ReDoS - esto era insuficiente, as\u00ed como _suficiente para someter al servidor a ReDoS si el administrador de la organizaci\u00f3n introduc\u00eda una expresi\u00f3n regular no v\u00e1lida suficientemente compleja. Los usuarios afectados deber\u00edan [actualizar a la reci\u00e9n estrenada Zulip versi\u00f3n 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), o [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)"
    }
  ],
  "id": "CVE-2021-41115",
  "lastModified": "2024-11-21T06:25:30.013",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "SINGLE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 4.0,
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:S/C:N/I:N/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 8.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-10-07T23:15:08.027",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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