ubuntu-cve-2021-3516
Vulnerability from osv_ubuntu
Published
2021-06-01 14:15
Modified
2026-04-22 07:39
Summary
Details

There's a flaw in libxml2's xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libxml2",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm2"
          },
          {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm2"
          },
          {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libxml2",
        "purl": "pkg:deb/ubuntu/libxml2@2.9.1+dfsg1-3ubuntu4.13+esm2?arch=source\u0026distro=trusty/esm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.9.1+dfsg1-3ubuntu4.13+esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.9.1+dfsg1-3ubuntu2",
        "2.9.1+dfsg1-3ubuntu3",
        "2.9.1+dfsg1-3ubuntu4",
        "2.9.1+dfsg1-3ubuntu4.1",
        "2.9.1+dfsg1-3ubuntu4.2",
        "2.9.1+dfsg1-3ubuntu4.3",
        "2.9.1+dfsg1-3ubuntu4.4",
        "2.9.1+dfsg1-3ubuntu4.5",
        "2.9.1+dfsg1-3ubuntu4.6",
        "2.9.1+dfsg1-3ubuntu4.7",
        "2.9.1+dfsg1-3ubuntu4.8",
        "2.9.1+dfsg1-3ubuntu4.9",
        "2.9.1+dfsg1-3ubuntu4.10",
        "2.9.1+dfsg1-3ubuntu4.11",
        "2.9.1+dfsg1-3ubuntu4.12",
        "2.9.1+dfsg1-3ubuntu4.13",
        "2.9.1+dfsg1-3ubuntu4.13+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libxml2",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm1"
          },
          {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm1"
          },
          {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libxml2",
        "purl": "pkg:deb/ubuntu/libxml2@2.9.3+dfsg1-1ubuntu0.7+esm1?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.9.3+dfsg1-1ubuntu0.7+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.9.2+zdfsg1-4",
        "2.9.2+zdfsg1-4ubuntu1",
        "2.9.2+zdfsg1-4ubuntu2",
        "2.9.2+zdfsg1-4ubuntu3",
        "2.9.3+dfsg1-1",
        "2.9.3+dfsg1-1ubuntu0.1",
        "2.9.3+dfsg1-1ubuntu0.2",
        "2.9.3+dfsg1-1ubuntu0.3",
        "2.9.3+dfsg1-1ubuntu0.4",
        "2.9.3+dfsg1-1ubuntu0.5",
        "2.9.3+dfsg1-1ubuntu0.6",
        "2.9.3+dfsg1-1ubuntu0.7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.4"
          },
          {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.4"
          },
          {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.4"
          },
          {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libxml2",
        "purl": "pkg:deb/ubuntu/libxml2@2.9.4+dfsg1-6.1ubuntu1.4?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.9.4+dfsg1-6.1ubuntu1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.9.4+dfsg1-4ubuntu1",
        "2.9.4+dfsg1-5ubuntu1",
        "2.9.4+dfsg1-5ubuntu2",
        "2.9.4+dfsg1-5.1ubuntu1",
        "2.9.4+dfsg1-5.2ubuntu1",
        "2.9.4+dfsg1-6.1ubuntu1",
        "2.9.4+dfsg1-6.1ubuntu1.2",
        "2.9.4+dfsg1-6.1ubuntu1.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.1"
          },
          {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.1"
          },
          {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.1"
          },
          {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libxml2",
        "purl": "pkg:deb/ubuntu/libxml2@2.9.10+dfsg-5ubuntu0.20.04.1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.9.10+dfsg-5ubuntu0.20.04.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.9.4+dfsg1-7ubuntu3",
        "2.9.4+dfsg1-7ubuntu5",
        "2.9.4+dfsg1-8ubuntu1",
        "2.9.4+dfsg1-8ubuntu2",
        "2.9.4+dfsg1-8ubuntu3",
        "2.9.10+dfsg-1ubuntu3",
        "2.9.10+dfsg-4build1",
        "2.9.10+dfsg-5"
      ]
    }
  ],
  "aliases": [],
  "details": "There\u0027s a flaw in libxml2\u0027s xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability.",
  "id": "UBUNTU-CVE-2021-3516",
  "modified": "2026-04-22T07:39:46Z",
  "published": "2021-06-01T14:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3516"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.gnome.org/GNOME/libxml2/-/issues/230"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.gnome.org/GNOME/libxml2/-/commit/1358d157d0bd83be1dfe356a69213df9fac0b539"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4991-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-3516"
    }
  ],
  "related": [
    "USN-4991-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-3516"
  ]
}



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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.
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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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