ubuntu-cve-2021-33912
Vulnerability from osv_ubuntu
Published
2022-01-19 18:15
Modified
2026-04-22 07:40
Summary
Details

libspf2 before 1.2.11 has a four-byte heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of incorrect sprintf usage in SPF_record_expand_data in spf_expand.c. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libmail-spf-xs-perl",
            "binary_version": "1.2.10-6ubuntu0.1~esm2"
          },
          {
            "binary_name": "libspf2-2",
            "binary_version": "1.2.10-6ubuntu0.1~esm2"
          },
          {
            "binary_name": "spfquery",
            "binary_version": "1.2.10-6ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libspf2",
        "purl": "pkg:deb/ubuntu/libspf2@1.2.10-6ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.10-6ubuntu0.1~esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.10-6",
        "1.2.10-6build1",
        "1.2.10-6ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libmail-spf-xs-perl",
            "binary_version": "1.2.10-7ubuntu0.18.04.1~esm1"
          },
          {
            "binary_name": "libspf2-2",
            "binary_version": "1.2.10-7ubuntu0.18.04.1~esm1"
          },
          {
            "binary_name": "spfquery",
            "binary_version": "1.2.10-7ubuntu0.18.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libspf2",
        "purl": "pkg:deb/ubuntu/libspf2@1.2.10-7ubuntu0.18.04.1~esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.10-7ubuntu0.18.04.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.10-7build2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libmail-spf-xs-perl",
            "binary_version": "1.2.10-7+deb9u2build0.20.04.1"
          },
          {
            "binary_name": "libspf2-2",
            "binary_version": "1.2.10-7+deb9u2build0.20.04.1"
          },
          {
            "binary_name": "spfquery",
            "binary_version": "1.2.10-7+deb9u2build0.20.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libspf2",
        "purl": "pkg:deb/ubuntu/libspf2@1.2.10-7+deb9u2build0.20.04.1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.10-7+deb9u2build0.20.04.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.10-7build3",
        "1.2.10-7build4"
      ]
    }
  ],
  "aliases": [],
  "details": "libspf2 before 1.2.11 has a four-byte heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of incorrect sprintf usage in SPF_record_expand_data in spf_expand.c. The vulnerable code may be part of the supply chain of a site\u0027s e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.",
  "id": "UBUNTU-CVE-2021-33912",
  "modified": "2026-04-22T07:40:05Z",
  "published": "2022-01-19T18:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-33912"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/shevek/libspf2/commit/28faf4624a6a371b11afdb9820078d3b0ee3803d"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-6584-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-6584-2"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-33912"
    }
  ],
  "related": [
    "USN-6584-1",
    "USN-6584-2"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-33912"
  ]
}



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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.
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  • 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.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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