Ios XrOperating system · Cisco
CVE-2013-5498
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 · uneditedThe PPTP-ALG component in CRS Carrier Grade Services Engine (CGSE) and ASR 9000 Integrated Service Module (ISM) in Cisco IOS XR allows remote attackers to cause a denial of service (module reset) via crafted packet streams, aka Bug ID CSCue91963.
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 confidenceThe PPTP-ALG (Point-to-Point Tunneling Protocol Application Layer Gateway) component in Cisco IOS XR on CRS Carrier Grade Services Engine (CGSE) and ASR 9000 Integrated Service Module (ISM) contains a vulnerability where specially crafted PPTP packet streams can cause the module to reset, resulting in denial of service. The vulnerability is remotely exploitable without authentication.
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
Ios XrOperating system
all versionsCVSS 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
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 hardware platformDetermine if the Cisco IOS XR system is a CRS (Carrier Routing System) with CGSE (Carrier Grade Services Engine) module, or an ASR 9000 with ISM (Integrated Service Module). Use 'show platform' or 'show hw-module' commands to list installed modules.Affected if The hardware is CRS with CGSE or ASR 9000 with ISM module.
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Verify PPTP-ALG module statusCheck if the PPTP-ALG application layer gateway is loaded or active. On Cisco IOS XR, use 'show alg pptp' or check the CGSE/ISM module status with 'show cgse' or 'show im' commands. Look for PPTP-ALG in the output.Affected if PPTP-ALG module is loaded or running on the system.
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Check PPTP-ALG configurationExamine the running configuration for PPTP-ALG related settings. Use 'show running-config | include pptp' or review CGSE/ISM specific configurations with 'show configuration' commands.Affected if PPTP-ALG is explicitly configured or enabled in the configuration.
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Verify PPTP traffic handlingCheck if the system is processing PPTP (TCP port 1723) and GRE (protocol 47) traffic. Use 'show access-lists' or 'show policy-map interface' to see if PPTP traffic is being inspected or allowed through.Affected if PPTP traffic inspection or ALG processing is enabled for traffic flows.
The environment is affected if running Cisco IOS XR on CRS with CGSE or ASR 9000 ISM hardware AND the PPTP-ALG feature is enabled or configured to handle PPTP traffic.
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 dataIf PPTP is not required, disable the PPTP-ALG feature or block PPTP traffic at network boundaries. Apply Cisco IOS XR software updates when available. Implement rate limiting on affected modules as a compensating control.
Fix this in Ios Xr
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-5498 — 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-2013-5498 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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