{"id":"CVE-2021-28041","title":"ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.","summary":"ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-415"],"vendor":"openbsd","product":"openssh","affected":["openssh >= 8.2, < 8.5","fedora = 33","fedora = 34","cloud_backup","hci_management_node","solidfire","hci_compute_node_firmware","hci_storage_node_firmware","communications_offline_mediation_controller = 12.0.0.3.0","zfs_storage_appliance = 8.8"],"patched":["openssh 8.5"],"published":"2021-03-05","updated":"2026-10-14","sourceUpdated":"2026-10-14T12:17:10.697","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-28041","references":[{"url":"https://github.com/openssh/openssh-portable/commit/e04fd6dde16de1cdc5a4d9946397ff60d96568db","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQWGII3LQR4AOTPPFXGMTYE7UDEWIUKI/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ/","label":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202105-35","label":"cve@mitre.org"},{"url":"https://security.netapp.com/advisory/ntap-20210416-0002/","label":"cve@mitre.org"},{"url":"https://www.openssh.com/security.html","label":"cve@mitre.org"},{"url":"https://www.openssh.com/txt/release-8.5","label":"cve@mitre.org"},{"url":"https://www.openwall.com/lists/oss-security/2021/03/03/1","label":"cve@mitre.org"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","label":"cve@mitre.org"},{"url":"https://github.com/openssh/openssh-portable/commit/e04fd6dde16de1cdc5a4d9946397ff60d96568db","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQWGII3LQR4AOTPPFXGMTYE7UDEWIUKI/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202105-35","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20210416-0002/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openssh.com/security.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openssh.com/txt/release-8.5","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openwall.com/lists/oss-security/2021/03/03/1","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.03422,"epssPercentile":0.88634,"ingestedAt":"2026-10-14T12:29:10.816Z","slug":"CVE-2021-28041","body":"## Overview\n\nssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.\n\n## Affected\n\n- `openssh >= 8.2, < 8.5`\n- `fedora = 33`\n- `fedora = 34`\n- `cloud_backup`\n- `hci_management_node`\n- `solidfire`\n- `hci_compute_node_firmware`\n- `hci_storage_node_firmware`\n- `communications_offline_mediation_controller = 12.0.0.3.0`\n- `zfs_storage_appliance = 8.8`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `openssh 8.5`","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":39.1,"likelihood":0.7,"exploitation":0,"ransomware":0},"changes":[]}