CVE-2020-2102 Non-constant time HMAC comparison
Jenkins uses non-constant time HMAC comparison, potentially allowing attackers to bypass authentication via timing side-channel attacks.
- 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-2020-2102?
CVE-2020-2102 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 used a non-constant time comparison function when validating an HMAC.
Weakness: CWE-203
Which versions are affected by CVE-2020-2102?
5 open source packages ship an affected version, including org.jenkins-ci.main:jenkins-core and jenkins. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.jenkins-ci.main:jenkins-core Maven | All versions | 2.204.2 |
org.jenkins-ci.main:jenkins-core Maven | All versions | 2.204.2 |
org.jenkins-ci.main:jenkins-core Maven | From 2.205 | 2.219 |
org.jenkins-ci.main:jenkins-core Maven | From 2.205 | 2.219 |
jenkins Bitnami | All versions | 2.218.1 |
Products include Jenkins Jenkins.
How do I fix CVE-2020-2102?
Upgrade org.jenkins-ci.main:jenkins-core to a fixed version for your release line: 2.204.2 or 2.219.
Is CVE-2020-2102 being exploited?
There is no known exploitation of CVE-2020-2102 in the wild and no public exploit code.
Other vulnerabilities in Jenkins Jenkins
- CVE-2024-23897 Jenkins Command Line Interface (CLI) Path Traversal
- CVE-2018-1000861 Jenkins Stapler Web Framework Deserialization of Untrusted Data
- CVE-2017-1000353 Jenkins Remote Code Execution
- CVE-2015-5317 Jenkins User Interface (UI) Information Disclosure
- CVE-2021-21690 Multiple vulnerabilities allow bypassing path filtering of agent-to-controller access control in Jenkins
Sources
Also known as BIT-jenkins-2020-2102, GHSA-fj6f-6933-839j.