Meeting ServerApplication · Cisco
CVE-2021-1524
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 · uneditedA vulnerability in the API of Cisco Meeting Server could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because requests that are sent to the API are not properly validated. An attacker could exploit this vulnerability by sending a malicious request to the API. A successful exploit could allow the attacker to cause all participants on a call to be disconnected, resulting in a DoS condition.
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 confidenceThe Cisco Meeting Server API lacks proper validation of incoming requests, allowing an authenticated remote attacker to send specially crafted API requests that cause all participants to be disconnected from calls, resulting in denial of service.
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
Meeting ServerApplication
>= 3.1, < 3.1.1CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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.
-
Identify installed Cisco Meeting Server versionAccess the admin interface or use the command line interface to retrieve the current version number of the Cisco Meeting Server softwareAffected if The installed version is greater than or equal to 3.1 but less than 3.1.1
-
Verify API access is enabledCheck the Cisco Meeting Server configuration to determine if the API interface is exposed and accessible to network clientsAffected if The API is enabled and reachable from network segments where potential attackers exist
-
Review API authentication configurationExamine the API authentication settings to determine which users or accounts have API access privilegesAffected if API access is granted to users beyond trusted administrators, increasing the attack surface
-
Check for unusual API activity in logsReview Cisco Meeting Server logs for API requests that may indicate exploitation attempts, particularly those targeting call participant management endpointsAffected if Logs show API requests that correlate with participant disconnections from calls
The environment is affected if Cisco Meeting Server version 3.1 through 3.1.0 is running with the API interface enabled and accessible to authenticated 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 data3.1.1
Apply the vendor patch from Cisco for CVE-2021-1524 to implement proper API request validation and prevent malicious requests from disconnecting call participants.
Fix this in Meeting Server
Scoped from the published advisory
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,040.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1524 — 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-2021-1524 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