#VU21574 Improper access control in Pipeline: Groovy - CVE-2018-1000866

Vulnerability identifier: #VU21574

Vulnerability risk: High

CVSSv4.0: 6.3 [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:U/U:Amber]

CVE-ID: CVE-2018-1000866

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Pipeline: Groovy
Web applications / Modules and components for CMS

Vendor: Jenkins

Description

The vulnerability allows a remote attacker to bypass sandbox restrictions.

The vulnerability exists in "groovy-sandbox/src/main/java/org/kohsuke/groovy/sandbox/SandboxTransformer.java" and "groovy-cps/lib/src/main/java/com/cloudbees/groovy/cps/SandboxCpsTransformer.java" due to the Groovy Sandbox library does not apply sandbox restrictions to finalize methods. A remote authenticated attacker with Job/Configure permission, or non-authenticated attacker with SCM commit privileges and corresponding pipelines based on Jenkins files set up in Jenkins, 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 - 2.59

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External links
https://jenkins.io/security/advisory/2018-10-29/#SECURITY-1186

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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.