iOSOperating system · Cisco
CVE-2009-5040
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 · uneditedCallManager Express (CME) on Cisco IOS before 15.0(1)XA allows remote authenticated users to cause a denial of service (device crash) by using an extension mobility (EM) phone to interact with the menu for SNR number changes, aka Bug ID CSCta63555.
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 confidenceCallManager Express (CME) on Cisco IOS before 15.0(1)XA contains a denial of service vulnerability where remote authenticated users can trigger a device crash by interacting with the extension mobility (EM) phone menu for SNR (Single Number Reach) number changes. The vulnerability is tracked as Cisco bug ID CSCta63555.
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
iOSOperating system
<= 15.0xa= 4.1= 4.1.1= 4.1.2= 7.2\(2\)22= 8.2= 8.3= 9.0= 9.1= 9.14= 10.0= 10.3CVSS 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
- Single
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:N/AC:L/Au:S/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.
-
Check Cisco IOS versionRun 'show version' and identify the IOS release number (e.g., 12.4, 15.0, etc.)Affected if The version matches any of these: <= 15.0xa, 4.1, 4.1.1, 4.1.2, 7.2(2)22, 8.2, 8.3, 9.0, 9.1, 9.14, 10.0, or 10.3
-
Confirm CallManager Express is runningRun 'show telephony-service' or 'show call-manager-fallback' to verify CME is configuredAffected if CME telephony service is active on the device
-
Verify Extension Mobility feature is enabledRun 'show extension mobility' or check telephony-service configuration for EM configurationAffected if Extension Mobility feature is configured and enabled for users or devices
-
Confirm Single Number Reach is in useRun 'show ephone' or 'showephone-dn' and look for SNR bindings or 'snr' keyword in the outputAffected if Single Number Reach (SNR) is configured on any extension or DN
A device is affected if it runs a vulnerable Cisco IOS version from the list AND has CME with Extension Mobility AND SNR features simultaneously enabled.
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 Cisco IOS to version 15.0(1)XA or later to resolve this vulnerability. Prior to upgrade, consider restricting CME management access to trusted networks and limiting extension mobility feature access to authorized users only.
Fix this in iOS
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-5040 — 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-2009-5040 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