Administrator access via retained pre-login session
Published Jun 30, 2021 · Updated Aug 3, 2024
Session fixation in Jenkins 2.266 through 2.299 and LTS 2.277.1 through 2.289.1 allows remote attackers to gain administrator access. Jenkins reuses the browser's existing HTTP session across a successful login instead of rotating or invalidating it, preserving an attacker-known session identifier. Exploitation requires social engineering that causes an administrator to authenticate within the attacker-established session; the resulting session carries the administrator's privileges.
Summary
What happened
Session fixation in Jenkins 2.266 through 2.299 and LTS 2.277.1 through 2.289.1 allows remote attackers to gain administrator access. Jenkins reuses the browser's existing HTTP session across a successful login instead of rotating or invalidating it, preserving an attacker-known session identifier. Exploitation requires social engineering that causes an administrator to authenticate within the attacker-established session; the resulting session carries the administrator's privileges.
The record
- CVE
- CVE-2021-21671
- Published
- Jun 30, 2021
- Updated
- Aug 3, 2024
- Vendor
- Jenkins Project
- Product
- Jenkins
- Classifications
- T1185
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 30, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.266 <unspecified
- Affected versionversion=LTS 2.277.1 <unspecified
- Affected versionversion=unspecified <=2.299
- Affected versionversion=unspecified <=LTS 2.289.1
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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