Unified Communications ManagerApplication · Cisco
CVE-2021-34773
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 web-based management interface of Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager Session Management Edition (Unified CM SME), and Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected device. This vulnerability is due to insufficient CSRF protections for the web-based management interface on an affected device. An attacker could exploit this vulnerability by persuading a user of the interface to click a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the targeted user. These actions could include modifying the device configuration and deleting (but not creating) user accounts.
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 confidenceA CSRF vulnerability in Cisco Unified CM, Unified CM SME, and Unified CM IM&P web-based management interface allows unauthenticated remote attackers to perform arbitrary actions by tricking authenticated users into clicking malicious links. The attacker can modify device configuration and delete user accounts due to insufficient CSRF protection mechanisms.
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
Unified Communications ManagerApplication
all versions= 14.0\(1.10000.20\)
Unified Communications Manager Im And Presence ServiceApplication
= 10.5\(2\)= 11.5\(1\)= 12.5= 14.0CVSS 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
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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 Cisco Unified CM web management interface exposureDetermine if the Cisco Unified Communications Manager web-based management interface (typically ports 443, 8443) is accessible from network locations where untrusted users could potentially send requests. Review firewall rules and access control lists.Affected if The web management interface is exposed to untrusted networks without proper network segmentation.
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Check Cisco Unified Communications Manager versionAccess the web management interface and navigate to About Cisco Unified Communications Manager or use the CLI command 'show version' to identify the installed version.Affected if The installed version is any version prior to patching, specifically versions matching: all versions; 14.0(1.10000.20); or versions 10.5(2), 11.5(1), 12.5, 14.0 of Unified CM IM&P.
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Verify SameSite cookie attributes on management interfaceLog into the web management interface using a browser with developer tools. Inspect the Set-Cookie headers and cookie attributes in the Application/Storage tab. Look for SameSite attribute on session cookies.Affected if Session cookies lack the SameSite attribute or have it set to None/Lax without Secure flag, indicating missing CSRF protection.
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Check for anti-CSRF tokens in web formsNavigate to a configuration form in the web management interface (e.g., Device > Phone, User Management). View the page source or use browser developer tools to inspect form submissions for hidden CSRF token fields.Affected if Forms lack hidden anti-CSRF token fields or the tokens are not validated on submission, allowing forged requests.
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Inspect HTTP response headers for CSRF protectionsUse a tool like curl or browser developer tools to capture HTTP responses from the management interface. Check for custom CSRF-related headers or security headers that indicate CSRF protection.Affected if No CSRF-related headers (such as custom anti-CSRF tokens) are present in HTTP responses.
A user is affected if the Cisco Unified CM or Unified CM IM&P web management interface is accessible and the installed version falls within the affected ranges without proper SameSite cookie attributes and anti-CSRF token protections in place.
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 dataApply Cisco's patch for this vulnerability and implement anti-CSRF tokens and SameSite cookie attributes in the web management interface to prevent forged requests.
Fix this in Unified Communications Manager
Scoped from the published advisory
- 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-2021-34773 — 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-2021-34773 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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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