CVE-2021-21602 Arbitrary file read vulnerability in workspace browsers in Jenkins

Medium 6.5 Published Updated

Attackers can read arbitrary files on the Jenkins server by exploiting symlink following in the workspace and artifact file browsers.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2021-21602?

CVE-2021-21602 is a medium-severity path traversal vulnerability in Jenkins Jenkins, published on 13 Jan 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier allows reading arbitrary files using the file browser for workspaces and archived artifacts by following symlinks.

Weakness: CWE-59

Which versions are affected by CVE-2021-21602?

5 open source packages ship an affected version, including org.jenkins-ci.main:jenkins-core and jenkins. It affects 1 product.

PackageAffectedFixed in
org.jenkins-ci.main:jenkins-core MavenAll versions2.263.2
org.jenkins-ci.main:jenkins-core MavenAll versions2.263.2
org.jenkins-ci.main:jenkins-core MavenFrom 2.2642.275
org.jenkins-ci.main:jenkins-core MavenFrom 2.2642.275
jenkins BitnamiAll versions2.274.1

Products include Jenkins Jenkins.

How do I fix CVE-2021-21602?

Upgrade org.jenkins-ci.main:jenkins-core to a fixed version for your release line: 2.263.2 or 2.275.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2021-21602 being exploited?

There is no known exploitation of CVE-2021-21602 in the wild and no public exploit code.

All Jenkins Jenkins vulnerabilities

Sources

Also known as BIT-jenkins-2021-21602, GHSA-vpjm-58cw-r8q5.

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