{"id":"CVE-2021-21696","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-21696","generatedAt":"2026-10-28T02:58:47.425Z","title":"Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted…","description":"Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted library with a modified variant. This results in unsandboxed code execution in the Jenkins controller process.","published":"2021-11-04T17:15:09.000Z","lastModified":"2026-06-17T03:36:01.000Z","status":"Modified","sourceIdentifier":"jenkinsci-cert@googlegroups.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":["jenkins/jenkins"],"epss":{"score":0.02397,"percentile":0.83892,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2021/11/04/3","tags":["Mailing List","Third Party Advisory"],"source":"jenkinsci-cert@googlegroups.com"},{"url":"https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423","tags":["Mitigation","Vendor Advisory"],"source":"jenkinsci-cert@googlegroups.com"},{"url":"http://www.openwall.com/lists/oss-security/2021/11/04/3","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423","tags":["Mitigation","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21696","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}