ubuntu-cve-2021-26717
Vulnerability from osv_ubuntu
Published
2021-02-18 20:15
Modified
2026-05-20 14:53
Summary
Details

An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "asterisk",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-config",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-dahdi",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-mobile",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-modules",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-mp3",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-mysql",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-ooh323",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-tests",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          },
          {
            "binary_name": "asterisk-vpb",
            "binary_version": "1:18.10.0~dfsg+~cs6.10.40431411-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "asterisk",
        "purl": "pkg:deb/ubuntu/asterisk@1:18.10.0~dfsg+~cs6.10.40431411-2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:16.16.1~dfsg-2",
        "1:16.16.1~dfsg-4",
        "1:16.16.1~dfsg-4build1",
        "1:16.16.1~dfsg+~2.10-1",
        "1:18.10.0~dfsg+~cs6.10.40431411-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "asterisk",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-config",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-dahdi",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-mobile",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-modules",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-mp3",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-mysql",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-ooh323",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          },
          {
            "binary_name": "asterisk-tests",
            "binary_version": "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "asterisk",
        "purl": "pkg:deb/ubuntu/asterisk@1:20.6.0~dfsg+~cs6.13.40431414-2build5?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:20.4.0~dfsg+~cs6.13.40431414-2",
        "1:20.5.0~dfsg+~cs6.13.40431414-1",
        "1:20.5.1~dfsg+~cs6.13.40431414-1",
        "1:20.5.2~dfsg+~cs6.13.40431414-1",
        "1:20.6.0~dfsg+~cs6.13.40431414-1",
        "1:20.6.0~dfsg+~cs6.13.40431414-2",
        "1:20.6.0~dfsg+~cs6.13.40431414-2build3",
        "1:20.6.0~dfsg+~cs6.13.40431414-2build4",
        "1:20.6.0~dfsg+~cs6.13.40431414-2build5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "asterisk",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-config",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-dahdi",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mobile",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-modules",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mp3",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mysql",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-ooh323",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-tests",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "asterisk",
        "purl": "pkg:deb/ubuntu/asterisk@1:22.5.2~dfsg+~cs6.15.60671435-1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:22.2.0~dfsg+~cs6.15.60671435-2",
        "1:22.3.0~dfsg+~cs6.15.60671435-1",
        "1:22.4.1~dfsg+~cs6.15.60671435-1",
        "1:22.4.1~dfsg+~cs6.15.60671435-2",
        "1:22.5.1~dfsg+~cs6.15.60671435-1",
        "1:22.5.2~dfsg+~cs6.15.60671435-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "asterisk",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-config",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-dahdi",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mobile",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-modules",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mp3",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-mysql",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-ooh323",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          },
          {
            "binary_name": "asterisk-tests",
            "binary_version": "1:22.5.2~dfsg+~cs6.15.60671435-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "asterisk",
        "purl": "pkg:deb/ubuntu/asterisk@1:22.5.2~dfsg+~cs6.15.60671435-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:22.5.2~dfsg+~cs6.15.60671435-1"
      ]
    }
  ],
  "aliases": [],
  "details": "An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.",
  "id": "UBUNTU-CVE-2021-26717",
  "modified": "2026-05-20T14:53:10Z",
  "published": "2021-02-18T20:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-26717"
    },
    {
      "type": "REPORT",
      "url": "http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html"
    },
    {
      "type": "REPORT",
      "url": "http://seclists.org/fulldisclosure/2021/Feb/58"
    },
    {
      "type": "REPORT",
      "url": "https://downloads.asterisk.org/pub/security/"
    },
    {
      "type": "REPORT",
      "url": "https://downloads.asterisk.org/pub/security/AST-2021-002.html"
    },
    {
      "type": "REPORT",
      "url": "https://issues.asterisk.org/jira/browse/ASTERISK-29203"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-26717"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/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-2021-26717"
  ]
}



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