UBUNTU-CVE-2025-5372 (CVE-2025-5372)

Vulnerability from osv_ubuntu – Published: 2025-06-25 00:00 – Updated: 2026-04-22 07:53 – Source website
VLAI
Details

A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success—the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality, integrity, and availability.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm5"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.6.3-4.3ubuntu0.6+esm5?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.6.3-3ubuntu3",
        "0.6.3-4.1",
        "0.6.3-4.2",
        "0.6.3-4.2ubuntu1",
        "0.6.3-4.3",
        "0.6.3-4.3ubuntu0.1",
        "0.6.3-4.3ubuntu0.2",
        "0.6.3-4.3ubuntu0.5",
        "0.6.3-4.3ubuntu0.6",
        "0.6.3-4.3ubuntu0.6+esm1",
        "0.6.3-4.3ubuntu0.6+esm2",
        "0.6.3-4.3ubuntu0.6+esm3",
        "0.6.3-4.3ubuntu0.6+esm4",
        "0.6.3-4.3ubuntu0.6+esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.7.5-1",
        "0.8.0~20170825.94fa1e38-1",
        "0.8.0~20170825.94fa1e38-1build1",
        "0.8.0~20170825.94fa1e38-1ubuntu0.1",
        "0.8.0~20170825.94fa1e38-1ubuntu0.2",
        "0.8.0~20170825.94fa1e38-1ubuntu0.5",
        "0.8.0~20170825.94fa1e38-1ubuntu0.6",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm5",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6",
        "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm4"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.9.3-2ubuntu2.5+esm4?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.0-1ubuntu1",
        "0.9.0-1ubuntu4",
        "0.9.0-1ubuntu5",
        "0.9.3-2ubuntu1",
        "0.9.3-2ubuntu2",
        "0.9.3-2ubuntu2.1",
        "0.9.3-2ubuntu2.2",
        "0.9.3-2ubuntu2.3",
        "0.9.3-2ubuntu2.4",
        "0.9.3-2ubuntu2.5",
        "0.9.3-2ubuntu2.5+esm1",
        "0.9.3-2ubuntu2.5+esm2",
        "0.9.3-2ubuntu2.5+esm3",
        "0.9.3-2ubuntu2.5+esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.9.6-2ubuntu0.22.04.4"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.9.6-2ubuntu0.22.04.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.9.6-2ubuntu0.22.04.4?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.6-2ubuntu0.22.04.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.6-1",
        "0.9.6-1build1",
        "0.9.6-2",
        "0.9.6-2build1",
        "0.9.6-2ubuntu0.22.04.1",
        "0.9.6-2ubuntu0.22.04.2",
        "0.9.6-2ubuntu0.22.04.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssh-4",
            "binary_version": "0.10.6-2ubuntu0.1"
          },
          {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.10.6-2ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libssh",
        "purl": "pkg:deb/ubuntu/libssh@0.10.6-2ubuntu0.1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.10.6-2ubuntu0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.10.5-3ubuntu1",
        "0.10.5-3ubuntu2",
        "0.10.6-2",
        "0.10.6-2build1",
        "0.10.6-2build2"
      ]
    }
  ],
  "aliases": [],
  "details": "A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success\u2014the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions\u0027 confidentiality, integrity, and availability.",
  "id": "UBUNTU-CVE-2025-5372",
  "modified": "2026-04-22T07:53:18Z",
  "published": "2025-06-25T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-5372"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-5372"
    },
    {
      "type": "REPORT",
      "url": "https://www.libssh.org/security/advisories/CVE-2025-5372.txt"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-7619-1"
    }
  ],
  "related": [
    "USN-7619-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-5372"
  ]
}



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