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Session fixation vulnerability in Jenkins

High severity GitHub Reviewed Published May 24, 2022 to the GitHub Advisory Database • Updated Dec 6, 2023

Package

maven org.jenkins-ci.main:jenkins-core (Maven)

Affected versions

>= 2.292, <= 2.299
<= 2.289.1

Patched versions

2.300
2.289.2

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.

References

Published by the National Vulnerability Database Jun 30, 2021
Published to the GitHub Advisory Database May 24, 2022
Reviewed Dec 16, 2022
Last updated Dec 6, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS score

0.304%
(70th percentile)

Weaknesses

CVE ID

CVE-2021-21671

GHSA ID

GHSA-4wr9-2xc6-jmg5

Source code

Credits

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