{"id":"UBUNTU-CVE-2021-45444","details":"In zsh before 5.8.1, an attacker can achieve code execution if they control a command output inside the prompt, as demonstrated by a %F argument. This occurs because of recursive PROMPT_SUBST expansion.","modified":"2026-04-22T15:01:23.109557Z","published":"2022-02-14T12:15:00Z","related":["USN-5325-1"],"upstream":["CVE-2021-45444"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-45444"},{"type":"REPORT","url":"https://sourceforge.net/p/zsh/code/ci/c187154f47697cdbf822c2f9d714d570ed4a0fd1/"},{"type":"REPORT","url":"https://sourceforge.net/p/zsh/code/ci/fdb8b0ce6244ff26bf55e0fd825310a58d0d3156/"},{"type":"REPORT","url":"https://sourceforge.net/p/zsh/code/ci/bdc4d70a7e033b754e68a8659a037ea0fc5f38de/"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5325-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-45444"}],"affected":[{"package":{"name":"zsh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/zsh@5.1.1-1ubuntu2.3+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.1.1-1ubuntu2.3+esm1"}]}],"versions":["5.1.1-1ubuntu1","5.1.1-1ubuntu2","5.1.1-1ubuntu2.1","5.1.1-1ubuntu2.2","5.1.1-1ubuntu2.3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"zsh","binary_version":"5.1.1-1ubuntu2.3+esm1"},{"binary_name":"zsh-common","binary_version":"5.1.1-1ubuntu2.3+esm1"},{"binary_name":"zsh-static","binary_version":"5.1.1-1ubuntu2.3+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-45444.json"}},{"package":{"name":"zsh","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/zsh@5.4.2-3ubuntu3.2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.2-3ubuntu3.2"}]}],"versions":["5.2-5ubuntu1","5.4.2-3ubuntu1","5.4.2-3ubuntu2","5.4.2-3ubuntu3","5.4.2-3ubuntu3.1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"zsh","binary_version":"5.4.2-3ubuntu3.2"},{"binary_name":"zsh-common","binary_version":"5.4.2-3ubuntu3.2"},{"binary_version":"5.4.2-3ubuntu3.2","binary_name":"zsh-static"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-45444.json"}},{"package":{"name":"zsh","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/zsh@5.8-3ubuntu1.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.8-3ubuntu1.1"}]}],"versions":["5.7.1-1ubuntu2","5.8-2ubuntu2","5.8-3ubuntu1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"zsh","binary_version":"5.8-3ubuntu1.1"},{"binary_name":"zsh-common","binary_version":"5.8-3ubuntu1.1"},{"binary_name":"zsh-static","binary_version":"5.8-3ubuntu1.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-45444.json"}},{"package":{"name":"zsh","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/zsh@5.8.1-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.8-6build1","5.8-10","5.8.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.8.1-1","binary_name":"zsh"},{"binary_version":"5.8.1-1","binary_name":"zsh-common"},{"binary_name":"zsh-static","binary_version":"5.8.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-45444.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"low"}]}