CVE-2021-21823
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 · uneditedAn information disclosure vulnerability exists in the Friend finder functionality of GmbH Komoot version 10.26.9 up to 11.1.11. A specially crafted series of network requests can lead to the disclosure of sensitive information.
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 confidenceAn information disclosure vulnerability exists in Komoot's Friend finder functionality (versions 10.26.9 to 11.1.11). The vulnerability is triggered through a specially crafted series of network requests, likely exploiting improper access controls or enumeration issues in the friend discovery API endpoints, allowing attackers to access sensitive user information without proper authorization.
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>= 10.26.9, <= 11.1.11CVSS 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
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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.
-
Check installed Komoot versionOpen Komoot app > Go to Profile > Tap settings icon > Scroll to About or version info. Alternatively, check in Google Play Store or Apple App Store listing, or device Settings > Apps > Komoot > VersionAffected if Version number is >= 10.26.9 and <= 11.1.11
-
Confirm friend finder feature is enabledNavigate to Komoot app settings and check if Friend Finder or friend discovery features are active or connected to contacts/social accountsAffected if Friend finder functionality is enabled and the app version falls within the affected range
-
Review API access logs for friend discovery endpointsIf you have access to Komoot API logs or proxy logs, inspect network traffic for requests to friend finder endpoints (typically /friends, /discover, or similar) for signs of unauthorized enumeration or repeated requestsAffected if Logs show excessive or unauthorized requests to friend finder API endpoints from external sources without proper authorization headers
If Komoot version 10.26.9 through 11.1.11 is installed AND the friend finder feature is in use, the environment is likely affected by this information disclosure vulnerability.
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 to Komoot version 11.1.12 or later. Additionally, implement proper authorization checks and rate limiting on all friend finder API endpoints to prevent information disclosure through repeated network requests.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21823 — 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-2021-21823 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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