iOSOperating system · Cisco
CVE-2012-3062
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 · uneditedCisco IOS before 15.1(1)SY, when Multicast Listener Discovery (MLD) snooping is enabled, allows remote attackers to cause a denial of service (CPU consumption or device crash) via MLD packets on a network that contains many IPv6 hosts, aka Bug ID CSCtr88193.
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 prior to 15.1(1)SY when MLD snooping is enabled. Remote attackers can send crafted Multicast Listener Discovery (MLD) packets on IPv6 networks with many hosts, causing excessive CPU consumption or device crash. The vulnerability requires MLD snooping to be enabled on the targeted device.
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
= 15.1CVSS 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
- Adjacent
- Complexity
- M
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:A/AC:M/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 the Cisco IOS versionExecute 'show version' on the device CLI and locate the version string in the output (typically the first line, e.g., 'Cisco IOS Software, Version 15.1(1)T' or similar)Affected if The version string begins with '15.1' and is earlier than 15.1(1)SY (such as 15.1, 15.1(1), 15.1(1)T, 15.1(2), etc.)
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Verify MLD snooping is enabledExecute 'show ipv6 mld snooping' and examine the output for the operational statusAffected if The output shows 'MLD snooping is running' or indicates MLD snooping is enabled on one or more VLANs
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Confirm IGMP snooping configuration (alternate check)Execute 'show ip igmp snooping' and review whether snooping is activeAffected if Snooping is reported as enabled (this may indicate MLD snooping is also active on the device)
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Check for recent crash or high CPU eventsExecute 'show stack' or 'show log' and look for unexpected reloads or error messages related to multicast processingAffected if Device has experienced unexplained reloads or CPU spikes coinciding with IPv6 multicast traffic on the network
The device is affected if it runs any Cisco IOS version prior to 15.1(1)SY and has MLD snooping enabled, as this combination allows the crafted MLD packets to trigger excessive CPU consumption or a device crash.
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)SY or later. If upgrading is not immediately feasible, evaluate disabling MLD snooping if the network does not require it, though this may impact IPv6 multicast functionality.
Fix this in iOS
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-3062 — 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-2012-3062 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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