UBUNTU-CVE-2021-39191 (CVE-2021-39191)

Vulnerability from osv_ubuntu – Published: 2021-09-03 14:15 – Updated: 2025-10-24 04:50 – Source website
VLAI
Details

mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In versions prior to 2.4.9.4, the 3rd-party init SSO functionality of mod_auth_openidc was reported to be vulnerable to an open redirect attack by supplying a crafted URL in the target_link_uri parameter. A patch in version 2.4.9.4 made it so that the OIDCRedirectURLsAllowed setting must be applied to the target_link_uri parameter. There are no known workarounds aside from upgrading to a patched version.

Severity
4.7 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libapache2-mod-auth-openidc",
            "binary_version": "2.3.3-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libapache2-mod-auth-openidc",
        "purl": "pkg:deb/ubuntu/libapache2-mod-auth-openidc@2.3.3-1build1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.1.6-1",
        "2.3.1-2",
        "2.3.2-1",
        "2.3.2-1build1",
        "2.3.3-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libapache2-mod-auth-openidc",
            "binary_version": "2.4.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libapache2-mod-auth-openidc",
        "purl": "pkg:deb/ubuntu/libapache2-mod-auth-openidc@2.4.1-1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.3.10.2-1",
        "2.4.0.4-1",
        "2.4.1-1"
      ]
    }
  ],
  "aliases": [],
  "details": "mod_auth_openidc is an authentication/authorization module for the Apache 2.x HTTP server that functions as an OpenID Connect Relying Party, authenticating users against an OpenID Connect Provider. In versions prior to 2.4.9.4, the 3rd-party init SSO functionality of mod_auth_openidc was reported to be vulnerable to an open redirect attack by supplying a crafted URL in the `target_link_uri` parameter. A patch in version 2.4.9.4 made it so that the `OIDCRedirectURLsAllowed` setting must be applied to the `target_link_uri` parameter. There are no known workarounds aside from upgrading to a patched version.",
  "id": "UBUNTU-CVE-2021-39191",
  "modified": "2025-10-24T04:50:29Z",
  "published": "2021-09-03T14:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-39191"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/zmartzone/mod_auth_openidc/issues/672"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/zmartzone/mod_auth_openidc/commit/03e6bfb446f4e3f27c003d30d6a433e5dd8e2b3d"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/zmartzone/mod_auth_openidc/releases/tag/v2.4.9.4"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/zmartzone/mod_auth_openidc/security/advisories/GHSA-2pgf-8h6h-gqg2"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-39191"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-39191"
  ]
}



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