FreeBSDOperating system
CVE-2012-5363
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 IPv6 implementation in FreeBSD and NetBSD (unknown versions, year 2012 and earlier) allows remote attackers to cause a denial of service via a flood of ICMPv6 Neighbor Solicitation messages, a different vulnerability than CVE-2011-2393.
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 IPv6 implementation in FreeBSD and NetBSD contains a vulnerability that allows remote attackers to cause a denial of service by flooding the system with ICMPv6 Neighbor Solicitation messages, potentially exhausting system resources or causing a crash.
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
FreeBSDOperating system
< 9.2< 6.0.2CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 operating system and versionRun `uname -a` to display system information including OS name and version. For FreeBSD, also check `/usr/src/sys/sys/param.h` or `freebsd-version`. For NetBSD, check `uname -r` or examine `/etc/release`.Affected if The OS is FreeBSD version less than 9.2 or NetBSD version less than 6.0.2, AND IPv6 networking is enabled.
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Verify if IPv6 is enabledRun `ifconfig -a` or `ip -6 addr show` to list network interfaces and their IPv6 configuration. Check for any inet6 entries indicating active IPv6 addresses.Affected if IPv6 is active on any network interface, making the system reachable via IPv6 and potentially vulnerable to ICMPv6 Neighbor Solicitation floods.
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Check for existing ICMPv6 rate limitingExamine system configuration files such as `/etc/rc.conf` on FreeBSD or `/etc/sysctl.conf` on NetBSD for ICMPv6-related settings. Run `sysctl -a | grep icmp6` to view current ICMPv6 kernel parameters.Affected if No ICMPv6 rate limiting or filtering is configured, meaning the system has no defense against Neighbor Solicitation message floods.
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Review system logs for ICMPv6 anomaliesCheck system logs in `/var/log/messages`, `/var/log/system.log`, or use `dmesg` for recent entries containing 'icmp6', 'neighbor', or 'ndp' keywords that may indicate a Neighbor Solicitation flood.Affected if Logs show excessive ICMPv6 Neighbor Solicitation messages or system instability potentially linked to this vulnerability.
A system is affected if it runs FreeBSD before 9.2 or NetBSD before 6.0.2 with IPv6 enabled and no ICMPv6 rate limiting in place.
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 data6.0.29.2
Implement network-level rate limiting or filtering for ICMPv6 Neighbor Solicitation messages at the perimeter, and apply vendor patches for FreeBSD and NetBSD when available.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-5363 — 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-2012-5363 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data