CVE-2020-2101 Non-constant time comparison of inbound TCP agent connection secret

What is CVE-2020-2101?

CVE-2020-2101 is a medium-severity vulnerability in Jenkins Jenkins, published on 29 Jan 2020. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Jenkins 2.218 and earlier, LTS 2.204.1 and earlier did not use a constant-time comparison function for validating connection secrets, which could potentially allow an attacker to use a timing attack to obtain this secret.

Weakness: CWE-203

Which versions are affected by CVE-2020-2101?

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

Products include Jenkins Jenkins.

How do I fix CVE-2020-2101?

Upgrade org.jenkins-ci.main:jenkins-core to a fixed version for your release line: 2.204.2 or 2.219.

Is CVE-2020-2101 being exploited?

There is no known exploitation of CVE-2020-2101 in the wild and no public exploit code.

Other vulnerabilities in Jenkins Jenkins

• CVE-2024-23897 Jenkins Command Line Interface (CLI) Path Traversal Exploited Critical 9.8
• CVE-2018-1000861 Jenkins Stapler Web Framework Deserialization of Untrusted Data Exploited Critical 9.8
• CVE-2017-1000353 Jenkins Remote Code Execution Exploited Critical 9.8
• CVE-2015-5317 Jenkins User Interface (UI) Information Disclosure Exploited High 7.5
• CVE-2021-21690 Multiple vulnerabilities allow bypassing path filtering of agent-to-controller access control in Jenkins Critical 9.8

All Jenkins Jenkins vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-jenkins-2020-2101, GHSA-w7jr-wqw6-54xc.