Unified CallmanagerApplication · Cisco
CVE-2007-5537
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 · uneditedCisco Unified Communications Manager (CUCM, formerly CallManager) 5.1 before 5.1(2), and Unified CallManager 5.0, allow remote attackers to cause a denial of service (kernel panic) via a flood of SIP INVITE messages to UDP port 5060, which triggers resource exhaustion, aka CSCsi75822.
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 confidenceA remote denial of service vulnerability exists in Cisco Unified Communications Manager (CUCM) 5.1 before version 5.1(2) and Unified CallManager 5.0. Attackers can flood SIP INVITE messages to UDP port 5060, causing resource exhaustion that leads to a kernel panic and system failure.
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 CallmanagerApplication
= 5.0
Unified Communications ManagerApplication
<= 5.1\(2\)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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:N/AC:L/Au:N/C:N/I:N/A:C
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 CUCM installation directory or check system services for 'Cisco Unified Communications Manager' or 'CallManager' processes. Common paths include /usr/local/cm or check service status via 'show tech' commands accessible through the CUCM admin interface.Affected if The product Cisco Unified CallManager or CUCM is found on the system
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Determine installed CUCM versionAccess CUCM Administration interface, navigate to About > Version, or use CLI command 'show version' if SSH access is available. The version number displays in the format 5.0, 5.1(1), 5.1(2), etc.Affected if Installed version is exactly 5.0 or is 5.1, 5.1(1), or 5.1(2) (any version <= 5.1(2) excluding 5.1(2))
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Verify SIP service is enabled on UDP port 5060Check CUCM Service Parameters for Cisco SIP Proxy service or examine network listening ports. Use 'netstat -an | grep 5060' or equivalent to confirm UDP port 5060 is in LISTENING state.Affected if UDP port 5060 is open and listening for SIP traffic
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Confirm SIP INVITE handling is activeReview CUCM SIP configuration in Service Parameters > Cisco SIP Proxy. Check if SIP trunk or gateway is configured to accept INVITE requests. Review system logs for recent SIP INVITE activity.Affected if SIP service is active and processing INVITE messages on the vulnerable port
You are affected if Cisco Unified CallManager 5.0 or CUCM version 5.1 through 5.1(2) is installed with SIP service enabled and listening on UDP port 5060.
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 CUCM 5.1(2) or later. Implement SIP traffic rate limiting, firewall rules, or IPS/IDS signatures to filter or throttle excessive SIP INVITE requests at the network perimeter.
Fix this in Unified Callmanager
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2007-5537 — 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-2007-5537 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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- Version or environment caveats, and links to real fixes
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