iOSOperating system · Cisco
CVE-2012-5032
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 Flex-VPN load-balancing feature in the ipsec-ikev2 implementation in Cisco IOS before 15.1(1)SY3 does not require authentication, which allows remote attackers to trigger the forwarding of VPN traffic to an attacker-controlled destination, or the discarding of this traffic, by arranging for an arbitrary device to become a cluster member, aka Bug ID CSCub93641.
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 confidenceThe Flex-VPN load-balancing feature in Cisco IOS ipsec-ikev2 implementation lacks authentication requirements, allowing remote attackers to add arbitrary devices as cluster members. This enables traffic redirection to attacker-controlled destinations or traffic discard.
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
<= 15.1\(1\)sy2= 15.1= 15.1\(1\)sy= 15.1\(1\)sy1CVSS 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
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:P/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 Cisco IOS versionRun 'show version' command and locate the IOS release line (e.g., 'Version 15.1(1)SY1')Affected if Version is 15.1, 15.1(1)sy, 15.1(1)sy1, or 15.1(1)sy2 or earlier (15.1(1)sy3 and later are fixed)
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Verify Flex-VPN load-balancing is configuredRun 'show running-config | include flex' or 'show running-config | include load-balancing' to search for Flex-VPN related configurationAffected if Flex-VPN load-balancing feature is present in the configuration
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Check IKEv2 profile configurationRun 'show crypto ikev2 profile' to display configured IKEv2 profilesAffected if IKEv2 profiles exist and Flex-VPN is being used with IKEv2
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Inspect IPsec transform set and tunnel configurationRun 'show crypto ipsec transform-set' and 'show crypto ipsec tunnel' to identify IPsec tunnels using IKEv2Affected if IPsec tunnels are established using IKEv2 with Flex-VPN load-balancing enabled
The device is affected if it runs Cisco IOS version 15.1 through 15.1(1)sy2 and has Flex-VPN load-balancing configured with IKEv2, allowing unauthenticated remote attackers to manipulate cluster membership.
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 15.1(1)SY3 or later to patch the authentication bypass. If immediate upgrade is not feasible, restrict network access to the IKEv2 management interfaces using ACLs.
Fix this in iOS
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-5032 — 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-2012-5032 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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