{"id":"USN-5232-1","summary":"fail2ban vulnerability","details":"Jakub Żoczek discovered that certain Fail2ban actions handled whois responses in\nan insecure way. If Fail2ban was configured to use certain mail actions\nlike 'mail-whois' on a target system, a remote attacker who was able to control whois\nresponses to this target system could possibly execute arbitrary code.\n","modified":"2026-06-29T13:49:35.494993045Z","published":"2022-09-12T07:45:30Z","related":["UBUNTU-CVE-2021-32749"],"upstream":["CVE-2021-32749","UBUNTU-CVE-2021-32749"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5232-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-32749"}],"affected":[{"package":{"name":"fail2ban","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/fail2ban?arch=source&distro=trusty%2Fesm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.11-1ubuntu0.1~esm1"}]}],"versions":["0.8.10-3","0.8.11~pre1+git29-gccd2657-1","0.8.11-1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"fail2ban","binary_version":"0.8.11-1ubuntu0.1~esm1"}]},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:14.04:LTS","cves":[{"id":"CVE-2021-32749","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-5232-1.json"}},{"package":{"name":"fail2ban","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/fail2ban?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.3-1ubuntu0.1~esm1"}]}],"versions":["0.9.3-1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_version":"0.9.3-1ubuntu0.1~esm1","binary_name":"fail2ban"}]},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:16.04:LTS","cves":[{"id":"CVE-2021-32749","severity":[{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N","type":"CVSS_V3"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","type":"CVSS_V3"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-5232-1.json"}},{"package":{"name":"fail2ban","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/fail2ban?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.2-2ubuntu0.1~esm1"}]}],"versions":["0.9.7-2","0.10.2-1","0.10.2-2"],"ecosystem_specific":{"binaries":[{"binary_name":"fail2ban","binary_version":"0.10.2-2ubuntu0.1~esm1"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:18.04:LTS","cves":[{"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}],"id":"CVE-2021-32749"}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-5232-1.json"}},{"package":{"name":"fail2ban","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/fail2ban?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.11.1-1ubuntu0.1~esm1"}]}],"versions":["0.10.2-2.1","0.11.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.11.1-1ubuntu0.1~esm1","binary_name":"fail2ban"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-5232-1.json","cves_map":{"ecosystem":"Ubuntu:Pro:20.04:LTS","cves":[{"id":"CVE-2021-32749","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}]}}}],"schema_version":"1.7.5"}