#VU57987 Permissions, Privileges, and Access Controls in Jenkins and Jenkins LTS - CVE-2021-21694

Vulnerability identifier: #VU57987

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-21694

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Jenkins
Server applications / Application servers
Jenkins LTS
Server applications / Application servers

Vendor: Jenkins

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions within the FilePath#toURI, FilePath#hasSymlink, FilePath#absolutize, FilePath#isDescendant, and FilePath#get*DiskSpace, which leads to security restrictions bypass and privilege escalation.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Jenkins: 2.0 - 2.318

Jenkins LTS: 1.409.1 - 2.303.2

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External links
https://jenkins.io/security/advisory/2021-11-04/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.