{"id":"UBUNTU-CVE-2025-5372","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.","modified":"2026-04-22T16:05:14.565576Z","published":"2025-06-25T00:00:00Z","related":["USN-7619-1"],"upstream":["CVE-2025-5372"],"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"}],"affected":[{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.6.3-4.3ubuntu0.6+esm5?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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_version":"0.6.3-4.3ubuntu0.6+esm5","binary_name":"libssh-4"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.6.3-4.3ubuntu0.6+esm5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-5372.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-5372.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.9.3-2ubuntu2.5+esm4?arch=source&distro=esm-infra/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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":{"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"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-5372.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.9.6-2ubuntu0.22.04.4?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.6-2ubuntu0.22.04.4"}]}],"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":{"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"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-5372.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.10.6-2ubuntu0.1?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.6-2ubuntu0.1"}]}],"versions":["0.10.5-3ubuntu1","0.10.5-3ubuntu2","0.10.6-2","0.10.6-2build1","0.10.6-2build2"],"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"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-5372.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","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":"Ubuntu","score":"medium"}]}