{
  "schema_version": "1.7.0",
  "id": "USN-4635-1",
  "summary": "krb5 vulnerability",
  "details": "Demi Obenour discovered that Kerberos incorrectly handled certain ASN.1.\nAn attacker could possibly use this issue to cause a denial of service.\n",
  "aliases": [],
  "upstream": [
    "UBUNTU-CVE-2020-28196"
  ],
  "related": [],
  "published": "2020-11-17T13:35:56Z",
  "modified": "2026-04-22T07:36:58Z",
  "affected": [
    {
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.12+dfsg-2ubuntu5.4+esm2?arch=source&distro=trusty/esm"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.12+dfsg-2ubuntu5.4+esm2"
            }
          ]
        }
      ],
      "versions": [
        "1.10.1+dfsg-6.1ubuntu1",
        "1.11.3+dfsg-3ubuntu2",
        "1.12+dfsg-2ubuntu1",
        "1.12+dfsg-2ubuntu2",
        "1.12+dfsg-2ubuntu3",
        "1.12+dfsg-2ubuntu4",
        "1.12+dfsg-2ubuntu4.2",
        "1.12+dfsg-2ubuntu5",
        "1.12+dfsg-2ubuntu5.1",
        "1.12+dfsg-2ubuntu5.2",
        "1.12+dfsg-2ubuntu5.3",
        "1.12+dfsg-2ubuntu5.4",
        "1.12+dfsg-2ubuntu5.4+esm1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkadm5clnt-mit9",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkadm5srv-mit8",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkadm5srv-mit9",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkdb5-7",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.12+dfsg-2ubuntu5.4+esm2"
          }
        ],
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
      },
      "database_specific": {
        "cves_map": {
          "ecosystem": "Ubuntu:Pro:14.04:LTS",
          "cves": [
            {
              "id": "CVE-2020-28196",
              "severity": [
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "Ubuntu",
                  "score": "medium"
                }
              ]
            }
          ]
        }
      }
    },
    {
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.13.2+dfsg-5ubuntu2.2?arch=source&distro=xenial"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.13.2+dfsg-5ubuntu2.2"
            }
          ]
        }
      ],
      "versions": [
        "1.13.2+dfsg-2",
        "1.13.2+dfsg-3",
        "1.13.2+dfsg-4",
        "1.13.2+dfsg-5",
        "1.13.2+dfsg-5ubuntu1",
        "1.13.2+dfsg-5ubuntu2",
        "1.13.2+dfsg-5ubuntu2.1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkadm5clnt-mit9",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkadm5srv-mit9",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkdb5-8",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.13.2+dfsg-5ubuntu2.2"
          }
        ],
        "availability": "No subscription required"
      },
      "database_specific": {
        "cves_map": {
          "ecosystem": "Ubuntu:16.04:LTS",
          "cves": [
            {
              "id": "CVE-2020-28196",
              "severity": [
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "Ubuntu",
                  "score": "medium"
                }
              ]
            }
          ]
        }
      }
    },
    {
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.16-2ubuntu0.2?arch=source&distro=bionic"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.16-2ubuntu0.2"
            }
          ]
        }
      ],
      "versions": [
        "1.15.1-2",
        "1.16-2",
        "1.16-2build1",
        "1.16-2ubuntu0.1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkadm5clnt-mit11",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkadm5srv-mit11",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkdb5-9",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.16-2ubuntu0.2"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.16-2ubuntu0.2"
          }
        ],
        "availability": "No subscription required"
      },
      "database_specific": {
        "cves_map": {
          "ecosystem": "Ubuntu:18.04:LTS",
          "cves": [
            {
              "id": "CVE-2020-28196",
              "severity": [
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "Ubuntu",
                  "score": "medium"
                }
              ]
            }
          ]
        }
      }
    },
    {
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.17-6ubuntu4.1?arch=source&distro=focal"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.17-6ubuntu4.1"
            }
          ]
        }
      ],
      "versions": [
        "1.17-6",
        "1.17-6ubuntu3",
        "1.17-6ubuntu4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkadm5clnt-mit11",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkadm5srv-mit11",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkdb5-9",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.17-6ubuntu4.1"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.17-6ubuntu4.1"
          }
        ],
        "availability": "No subscription required"
      },
      "database_specific": {
        "cves_map": {
          "ecosystem": "Ubuntu:20.04:LTS",
          "cves": [
            {
              "id": "CVE-2020-28196",
              "severity": [
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "CVSS_V3",
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
                },
                {
                  "type": "Ubuntu",
                  "score": "medium"
                }
              ]
            }
          ]
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4635-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2020-28196"
    }
  ]
}