UBUNTU-CVE-2021-3517 (CVE-2021-3517)

Vulnerability from osv_ubuntu – Published: 2021-05-19 14:15 – Updated: 2026-04-22 07:39 – Source website
VLAI
Details

There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.

Severity
8.6 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
8.6 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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 is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.",
  "id": "UBUNTU-CVE-2021-3517",
  "modified": "2026-04-22T07:39:46Z",
  "published": "2021-05-19T14:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3517"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.gnome.org/GNOME/libxml2/-/issues/235"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.gnome.org/GNOME/libxml2/-/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4991-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-3517"
    }
  ],
  "related": [
    "USN-4991-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-3517"
  ]
}



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