Sandbox restrictions bypass in Pipeline: Groovy plugin for Jenkins

1) Improper access control

EUVDB-ID: #VU21572

Risk: High

CVSSv4.0: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2019-1003001

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to bypass sandbox restrictions.

The vulnerability exists due to improper access restrictions in "src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java" and "src/main/java/org/jenkinsci/plugins/workflow/cps/CpsGroovyShellFactory.java" when applying AST transforming annotations such as @Grab to source code elements. A remote authenticated attacker with Overall/Read permission, or able to control Jenkins file or sandboxed Pipeline shared library contents in SCM, can bypass the sandbox protection and execute arbitrary code on the Jenkins master.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Pipeline: Groovy: 2.0 - 2.61

CPE2.3

• cpe:2.3:a:jenkins:workflow-cps:2.0:*:*:*:*:jenkins:*:*
• cpe:2.3:a:jenkins:workflow-cps:2.1:*:*:*:*:jenkins:*:*
• cpe:2.3:a:jenkins:workflow-cps:2.2:*:*:*:*:jenkins:*:*

External links

https://packetstormsecurity.com/files/152132/Jenkins-ACL-Bypass-Metaprogramming-Remote-Code-Execution.html
https://jenkins.io/security/advisory/2019-01-08/#SECURITY-1266

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.