Unified Communications ManagerApplication · Cisco
CVE-2020-3135
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 (UCM) could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected device. The 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 follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the targeted user.
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 Communications Manager's web-based management interface allows unauthenticated remote attackers to trick authenticated administrators into unknowingly executing arbitrary actions. The flaw stems from missing or insufficient CSRF protections (tokens/referer validation) in the web interface, enabling attackers to forge valid requests by luring users to malicious links.
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
< 11.5\(1\)CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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.
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Identify Cisco Unified Communications Manager installationLocate the CUCM server and access its web management interface via HTTPS, typically on port 8443 or 443. Alternatively, check via CLI by logging into the server and running 'show version' or checking for CUCM-specific processes.Affected if The CUCM web management interface is accessible and responds to requests.
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Determine the installed CUCM versionLog into the Cisco Unified Communications Manager web interface as an administrator and navigate to the About page (usually under Help > About) to view the exact version number. From CLI, run 'show version detailed' or 'utils system version'.Affected if The displayed version is lower than 11.5(1), such as 11.0, 10.5, or earlier releases.
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Verify the web management interface is enabled and exposedConfirm the web-based management interface is active by attempting to access the CUCM admin login page. Check network exposure by reviewing firewall rules or listening services (netstat -an | grep -E '8443|443') to determine if the interface is reachable from external networks.Affected if The web management interface is enabled and accessible, particularly from untrusted networks.
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Inspect CSRF protection configurationReview the web application configuration files for CSRF token enforcement settings. In the CUCM web interface, examine the security settings or session configuration. Check if the application validates the Referer header or implements anti-CSRF tokens in forms.Affected if CSRF protections are missing, disabled, or improperly configured in the web management interface settings.
Your environment is affected if Cisco Unified Communications Manager is installed with a version lower than 11.5(1) and the web-based management interface is accessible and lacks proper CSRF protections.
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 data11.5
Apply the Cisco security patch for CVE-2020-3135 from Cisco's official advisories; temporarily mitigate by restricting web management interface access and educating users to avoid clicking untrusted links.
Fix this in Unified Communications Manager
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3135 — 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-2020-3135 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
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