iOSOperating system · Cisco
CVE-2009-2868
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 through 12.4, when certificate-based authentication is enabled for IKE, allows remote attackers to cause a denial of service (Phase 1 SA exhaustion) via crafted requests, aka Bug IDs CSCsy07555 and CSCee72997.
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 confidenceThis is a denial-of-service vulnerability in Cisco IOS versions 12.2 through 12.4 where remote attackers can exhaust Phase 1 Security Associations (SA) by sending specially crafted requests when certificate-based authentication is enabled for IKE (Internet Key Exchange) used in IPSec VPNs.
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
= 12.2ex= 12.2ira= 12.2irb= 12.2irc= 12.2sb= 12.2sca= 12.2scb= 12.2se= 12.2sra= 12.2srb= 12.2src= 12.2srdCVSS 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 CLI and locate the IOS release line (e.g., 12.2(SE) or similar). Compare the full version number against the affected variants: 12.2ex, 12.2ira, 12.2irb, 12.2irc, 12.2sb, 12.2sca, 12.2scb, 12.2se, 12.2sra, 12.2srb, 12.2src, 12.2srd.Affected if The device runs any of the listed 12.2 version variants.
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Verify IPSec VPN is configuredExecute 'show running-config | include crypto' or 'show crypto ipsec sa' to detect active IPSec VPN configuration.Affected if IPSec VPN tunnels or crypto policies are configured on the device.
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Confirm IKE is enabledExecute 'show running-config | include isakmp' or check for 'crypto isakmp' commands in the running configuration.Affected if IKE (Internet Key Exchange) is enabled via crypto isakmp policies.
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Check for certificate-based authenticationExecute 'show running-config | include certificate' or search for 'crypto isakmp certificate' and 'rsa enrollment' commands in the configuration.Affected if Certificate-based authentication is configured (rsa enrollment or crypto isakmp certificate commands are present).
The device is affected only if it runs an affected 12.2 IOS variant AND has certificate-based authentication enabled for IKE in an IPSec VPN configuration.
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 Cisco IOS patches corresponding to Bug IDs CSCsy07555 and CSCee72997, or upgrade to a fixed IOS version. If patches are unavailable, consider disabling certificate-based authentication for IKE or implementing rate limiting on IKE ports as a temporary workaround.
Fix this in iOS
Scoped from the published advisory
- Consultation8.0 h
- Implementation16.0 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 $10,240.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-2868 — 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-2009-2868 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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