JenkinsApplication
CVE-2020-2103
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedJenkins 2.218 and earlier, LTS 2.204.1 and earlier exposed session identifiers on a user's detail object in the whoAmI diagnostic page.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceJenkins versions 2.218 and earlier, along with LTS versions 2.204.1 and earlier, contain an information disclosure vulnerability where session identifiers are exposed on the user detail object accessible through the whoAmI diagnostic page. This allows authenticated users to potentially view session tokens belonging to other users.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
JenkinsApplication
<= 2.204.1<= 2.218CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine installed Jenkins versionAccess the Jenkins main page and look at the version displayed at the bottom right, or query the Jenkins API at /api/json to retrieve the 'version' fieldAffected if The installed version is Jenkins LTS 2.204.1 or earlier, or Jenkins weekly 2.218 or earlier
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Verify whoAmI diagnostic endpoint accessibilityNavigate to /whoAmI/ or access it via curl: curl -u <username>:<password> http://<jenkins-url>/whoAmI/api/jsonAffected if The endpoint returns user detail information without authentication errors (indicating authenticated users can access it)
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Inspect session identifier exposure in whoAmI responseExamine the JSON response from the whoAmI API endpoint for fields containing session tokens, session IDs, or authentication tokens associated with other usersAffected if The response contains session identifiers that belong to users other than the requesting user
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Confirm multi-user environmentNavigate to /securityRealm/ or /user/ to list all configured users in JenkinsAffected if More than one user account exists in the Jenkins instance, providing potential targets for session token theft
A user is affected if their Jenkins version is 2.204.1 or earlier (LTS) or 2.218 or earlier (weekly) AND the whoAmI endpoint exposes session identifiers belonging to other users.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade Jenkins to version 2.204.2 or later (LTS) or 2.219 or later (weekly) to remove the session identifier exposure from the whoAmI diagnostic page.
Fix this in Jenkins
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-2103 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-2103 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data