iOSOperating system · Cisco
CVE-2008-3813
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 · uneditedUnspecified vulnerability in Cisco IOS 12.2 and 12.4, when the L2TP mgmt daemon process is enabled, allows remote attackers to cause a denial of service (device reload) via a crafted L2TP packet.
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 IOS 12.2 and 12.4 when the L2TP (Layer 2 Tunneling Protocol) management daemon process is enabled. Attackers can send a specially crafted L2TP packet to cause the affected device to reload, resulting in complete service disruption.
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
= 12.2se= 12.2sg= 12.2srb= 12.4mr= 12.4sw= 12.4t= 12.4xj= 12.4xv= 12.4xwCVSS 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 IOS versionExecute 'show version' on the device and locate the software version line (typically begins with 'Cisco IOS Software' or 'Cisco Internetwork Operating System Software'). Note the full version string including the train number (e.g., 12.2se, 12.4t).Affected if The installed version matches one of: 12.2se, 12.2sg, 12.2srb, 12.4mr, 12.4sw, 12.4t, 12.4xj, 12.4xv, or 12.4xw.
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Determine if L2TP management daemon is enabledExecute 'show l2tp session' or 'show l2tp tunnel' to check for active L2TP sessions or tunnels. Also run 'show processes' or 'show processes cpu' and look for the L2TP management daemon process.Affected if L2TP sessions, tunnels, or the L2TP management daemon process is active or running on the device.
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Inspect L2TP configurationExecute 'show running-config | include l2tp' or 'show running-config | begin l2tp' to review the L2TP configuration in the active configuration.Affected if L2TP is configured (even if no active sessions exist), as the vulnerability can be triggered by receiving a crafted packet.
The device is affected if it runs any of the listed Cisco IOS versions AND has L2TP management daemon enabled or L2TP configured, regardless of whether active sessions are currently established.
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 dataDisable the L2TP mgmt daemon process if not required in the environment, and apply the relevant Cisco IOS security update or upgrade to a patched version.
Fix this in iOS
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2008-3813 — 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-2008-3813 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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