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openssh — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2011-0539

The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.

Products
openssh
Affected versions
Not specified
Fixed versions
1:5.8p1-2
CVEs
CVE-2011-0539
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 00:44 UTC · Revision 1

Source evidence

DEBIAN-CVE-2011-0539

core-osv · Original source

Published 10 Feb 2011, 18:00 UTC

The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.

osv:DEBIAN-CVE-2011-0539

openssh

Fixed versions: 1:5.8p1-2

openssh

Fixed versions: 1:5.8p1-2

openssh

Fixed versions: 1:5.8p1-2

Complete source record
{
  "id": "1ed39d92abc8df0cec88e3a58c2628ee8c42fa80205ddcf14e843278688b211b",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2011-0539",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2011-0539",
    "summary": "The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.",
    "evidence": "osv:DEBIAN-CVE-2011-0539",
    "products": [
      {
        "name": {
          "value": "openssh",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:5.8p1-2",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "openssh",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:5.8p1-2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "openssh",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1:5.8p1-2",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2011-0539",
      "aliases": [
        "DEBIAN-CVE-2011-0539"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:5.8p1-2"
                }
              ]
            }
          ],
          "package": {
            "name": "openssh",
            "purl": "pkg:deb/debian/openssh?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2011-0539.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:5.8p1-2"
                }
              ]
            }
          ],
          "package": {
            "name": "openssh",
            "purl": "pkg:deb/debian/openssh?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2011-0539.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1:5.8p1-2"
                }
              ]
            }
          ],
          "package": {
            "name": "openssh",
            "purl": "pkg:deb/debian/openssh?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2011-0539.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-23T18:03:40.266328793Z",
      "provider": "osv",
      "upstream": [
        "CVE-2011-0539"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2011-0539"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2011-0539",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 422149,
  "published_at": "2011-02-10T18:00:57.66+00:00"
}