{"id":"UBUNTU-CVE-2023-6004","details":"A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into the command of the features mentioned through the hostname parameter.","modified":"2026-04-22T14:34:48.628793Z","published":"2024-01-03T17:15:00Z","related":["USN-6592-1","USN-6592-2"],"upstream":["CVE-2023-6004"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-6004"},{"type":"REPORT","url":"https://vin01.github.io/piptagole/ssh/security/openssh/libssh/remote-code-execution/2023/12/20/openssh-proxycommand-libssh-rce.html"},{"type":"REPORT","url":"https://www.libssh.org/security/advisories/CVE-2023-6004.txt"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6592-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6592-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-6004"}],"affected":[{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.6.3-4.3ubuntu0.6+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.3-4.3ubuntu0.6+esm1"}]}],"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"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"libssh-4","binary_version":"0.6.3-4.3ubuntu0.6+esm1"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.6.3-4.3ubuntu0.6+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-6004.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3"}]}],"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"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"libssh-4","binary_version":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-6004.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.9.3-2ubuntu2.5?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.3-2ubuntu2.5"}]}],"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"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libssh-4","binary_version":"0.9.3-2ubuntu2.5"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.9.3-2ubuntu2.5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-6004.json"}},{"package":{"name":"libssh","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libssh@0.9.6-2ubuntu0.22.04.3?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.6-2ubuntu0.22.04.3"}]}],"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"],"ecosystem_specific":{"binaries":[{"binary_version":"0.9.6-2ubuntu0.22.04.3","binary_name":"libssh-4"},{"binary_name":"libssh-gcrypt-4","binary_version":"0.9.6-2ubuntu0.22.04.3"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-6004.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L"},{"type":"Ubuntu","score":"medium"}]}