ubuntu-cve-2021-28834
Vulnerability from osv_ubuntu
Published
2021-03-19 07:15
Modified
2025-07-18 16:46
Summary
Details

Kramdown before 2.3.1 does not restrict Rouge formatters to the Rouge::Formatters namespace, and thus arbitrary classes can be instantiated.

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": "No subscription required",
        "binaries": [
          {
            "binary_name": "kramdown",
            "binary_version": "1.17.0-4ubuntu0.2"
          },
          {
            "binary_name": "ruby-kramdown",
            "binary_version": "1.17.0-4ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "ruby-kramdown",
        "purl": "pkg:deb/ubuntu/ruby-kramdown@1.17.0-4ubuntu0.2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.17.0-4ubuntu0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.17.0-1",
        "1.17.0-2",
        "1.17.0-4",
        "1.17.0-4ubuntu0.1"
      ]
    }
  ],
  "aliases": [],
  "details": "Kramdown before 2.3.1 does not restrict Rouge formatters to the Rouge::Formatters namespace, and thus arbitrary classes can be instantiated.",
  "id": "UBUNTU-CVE-2021-28834",
  "modified": "2025-07-18T16:46:44Z",
  "published": "2021-03-19T07:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-28834"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/gettalong/kramdown/compare/REL_2_3_0...REL_2_3_1"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/gettalong/kramdown/pull/708"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.com/gitlab-org/gitlab/-/commit/179329b5c3c118924fb242dc449d06b4ed6ccb66"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-6424-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-28834"
    }
  ],
  "related": [
    "USN-6424-1"
  ],
  "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-2021-28834"
  ]
}



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