GHSA-4wr9-2xc6-jmg5 BIT-jenkins-2021-21671 CVE-2021-21671
Session fixation vulnerability in Jenkins
- Severity
- 7.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 1.75%
- Chance of exploitation in the next 30 days. Higher than 77.92% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-384 Session Fixation
- Fix
2.300- Upgrade org.jenkins-ci.main:jenkins-core to this version or later
Description
Jenkins 2.299 and earlier, LTS 2.289.1 and earlier does not invalidate the previous session on login. This allows attackers to use social engineering techniques to gain administrator access to Jenkins.
This vulnerability was introduced in Jenkins 2.266 and LTS 2.277.1.
Jenkins 2.300, LTS 2.289.2 invalidates the previous session on login.
In case of problems, administrators can choose a different implementation by setting the Java system property hudson.security.SecurityRealm.sessionFixationProtectionMode to 2, or disable the fix entirely by setting that system property to 0.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| org.jenkins-ci.main:jenkins-core | >= 2.292, < 2.300 |
2.300 |
| org.jenkins-ci.main:jenkins-core | < 2.289.2 |
2.289.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
org.jenkins-ci.main:jenkins-core Maven → 2.300
- maven
<dependency><groupId>org.jenkins-ci.main</groupId><artifactId>jenkins-core</artifactId><version>2.300</version></dependency>- gradle
implementation("org.jenkins-ci.main:jenkins-core:2.300")
Severity breakdown
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-384: Session Fixation
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
How to prevent it
- Architecture and Design: Invalidate any existing session identifiers prior to authorizing a new user session.
- Architecture and Design: For platforms such as ASP that do not generate new values for sessionid cookies, utilize a secondary cookie. In this approach, set a secondary cookie on the user's browser to a random value and set a session variable to the same value. If the session variable and the cookie value ever don't match, invalidate the session, and force the user to log on again.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-6f9g-cxwr-q5jr Arbitrary file read vulnerability through the Jenkins CLI can lead to RCE | Critical Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-8pqx-3rxx-f5pm Jenkins discloses project names via fingerprints | High Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-26wc-3wqp-g3rp Deserialization of Untrusted Data in Jenkins | Critical Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| CVE-2018-1000861 Deserialization of Untrusted Data in Jenkins | Critical Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-m6wv-wh8g-64xc Jenkins does not encrypt secrets from POST config.xml submissions before storing them in job configurations | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-93qh-vwrm-c5pw Jenkins: Stored XSS vulnerability in node offline cause description | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-92m7-4fpw-2wxm Jenkins: Open Redirect phishing attacks possible via "from" parameter in "Delegate to servlet container" | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-g28p-6mcc-v4rv Jenkins exposes other users' timezone and view names to users with Overall/Read permission | Medium | Also affects org.jenkins-ci.main:jenkins-core |
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