Emergency ResponderApplication · Cisco
CVE-2023-20259
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 an API endpoint of multiple Cisco Unified Communications Products could allow an unauthenticated, remote attacker to cause high CPU utilization, which could impact access to the web-based management interface and cause delays with call processing. This API is not used for device management and is unlikely to be used in normal operations of the device. This vulnerability is due to improper API authentication and incomplete validation of the API request. An attacker could exploit this vulnerability by sending a crafted HTTP request to a specific API on the device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to high CPU utilization, which could negatively impact user traffic and management access. When the attack stops, the device will recover without manual intervention.
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 confidenceUnauthenticated API endpoint vulnerability in Cisco Unified Communications Products allows remote attackers to cause denial of service via crafted HTTP requests. The vulnerability stems from improper authentication and incomplete validation of API requests, leading to high CPU utilization that impacts the web management interface and call processing.
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
Emergency ResponderApplication
= 14su3
Prime Collaboration DeploymentApplication
= 14su3
Unified Communications ManagerApplication
= 12.5\(1\)su7= 14su3
Unified Communications Manager Im \& Presence ServiceApplication
= 12.5\(1\)su7= 14su3
Unity ConnectionApplication
= 14su3CVSS 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
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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.
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Identify the installed Cisco Unified Communications productLog into the device via CLI and run 'show version' or access the web interface to identify the product name (e.g., Cisco Unified Communications Manager, Cisco Emergency Responder, Cisco Unity Connection)Affected if The product matches one of the affected products: Cisco Emergency Responder, Cisco Prime Collaboration Deployment, Cisco Unified Communications Manager, Cisco Unified Communications Manager IM & Presence Service, or Cisco Unity Connection
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Determine the exact software versionRun 'show version' in the CLI or check the 'About' page in the web interface. Note the full version string including the SU (Software Update) suffix (e.g., 14su3, 12.5(1)su7)Affected if The installed version is exactly 14su3, 12.5(1)su7, or matches the affected version notation for the product in question
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Verify if the web management interface is enabledCheck the Cisco Unified Communications Manager serviceability page or run 'utils service list' in the CLI to confirm if the Cisco Tomcat or web services are runningAffected if The web management interface (HTTP/HTTPS services) is enabled and accessible
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Check for network exposure of the management interfaceReview firewall rules, ACLs, or network segmentation config to determine if the web management port (TCP 8443, 443, or 80) is exposed to untrusted networksAffected if The management interface is reachable from external or untrusted networks without proper access controls
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Review HTTP access logs for unusual API requestsExamine logs under /var/log/httpd/ or use the Cisco Unified RTMT (Real Time Monitoring Tool) to search for high volumes of API endpoint requests that may indicate exploitation attemptsAffected if There is unexpected high CPU utilization correlated with unusual API request patterns in the logs
You are affected if you are running any of the listed Cisco Unified Communications products at versions 14su3, 12.5(1)su7 (or the specific su version noted) and the web management interface is exposed, as the vulnerability allows unauthenticated remote attackers to trigger high CPU usage via crafted HTTP requests to the API endpoint.
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 vendor-provided patches for Cisco Unified Communications Products to remediate the improper API authentication and input validation. Until patched, consider network-level controls to restrict access to the vulnerable API endpoint.
Fix this in Emergency Responder
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 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 $3,968.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20259 — 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-2023-20259 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
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