CVE-2021-25777
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 · uneditedIn JetBrains TeamCity before 2020.2.1, permissions during token removal were checked improperly.
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 · moderate confidenceThis is an authorization bypass vulnerability in JetBrains TeamCity where permission checks were improperly enforced during token removal operations. An authenticated user could potentially remove tokens they should not have been authorized to delete, compromising access control integrity.
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< 2020.2.1CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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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Identify TeamCity installation versionCheck the TeamCity server version through the Administration > Diagnostics > About page in the web UI, or look at the teamcity-server.log file in the logs directory for the build numberAffected if The installed version is any release prior to 2020.2.1 (e.g., 2020.2.0, 2020.1.x, earlier versions)
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Confirm token authentication is enabledNavigate to Administration > Authentication in the TeamCity web interface and verify if token-based authentication methods (user tokens, access tokens) are configured or availableAffected if Token authentication features are active or have been used in the system
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Review token ownership and access patternsCheck Administration > User Management > Tokens to enumerate existing tokens and identify which users have created tokens in the systemAffected if Multiple users have created tokens and there are tokens belonging to users other than the currently authenticated administrator reviewing the system
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Verify user role permissionsExamine the role assignments for users in Administration > User Management > Users and ensure that users who should not have token deletion permissions are not granted excessive privilegesAffected if Some users have elevated roles that could allow unauthorized token manipulation in versions prior to 2020.2.1
The environment is affected if the installed TeamCity version is any build earlier than 2020.2.1 and token-based authentication features are in use or have been configured.
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 data2020.2.1
Upgrade JetBrains TeamCity to version 2020.2.1 or later to receive the proper permission validation fix for token removal operations.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-25777 — 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-2021-25777 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
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