SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-21696

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…

CRITICAL 9.8EPSS 2.40%

Does this matter?

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.

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.40% probability · 83th percentile
CISA KEV
Not listed
Affected
jenkins/jenkins
Source
jenkinsci-cert@googlegroups.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.