CVE-2011-4093
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 · uneditedInteger overflow in inc/server.hpp in libnet6 (aka net6) before 1.3.14 might allow remote attackers to hijack connections and gain privileges as other users by making a large number of connections until the overflow occurs and an ID of another user is provided.
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 confidenceInteger overflow in inc/server.hpp in libnet6 (aka net6) before version 1.3.14 allows remote attackers to hijack connections and gain privileges as other users by making a large number of connections until the overflow occurs, causing user IDs to wrap and potentially be reassigned to new connections.
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= 11.2<= 1.3.13= 1.3.1= 1.3.2= 1.3.3= 1.3.4= 1.3.5= 1.3.6= 1.3.7= 1.3.8= 1.3.9= 1.3.10= 1.3.11= 11.3= 11.4CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- None
AV:N/AC:M/Au:N/C:P/I:P/A:N
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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Check if libnet6 is installedSearch for libnet6 package or library files. On Linux systems, use: rpm -qa | grep -i libnet6 or dpkg -l | grep -i net6. On Solaris, use: pkginfo | grep -i libnet6Affected if libnet6 package or library is found on the system
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Determine libnet6 versionIf using rpm: rpm -q libnet6. If using dpkg: dpkg -s libnet6. If the binary is present, try: net6 --version or check the library file version with: strings /path/to/libnet6.so | grep versionAffected if version is 1.3.13 or earlier, or the exact versions 1.3.1 through 1.3.11 listed in affected products
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Verify if the service using libnet6 is network-exposedIdentify any service using libnet6 (common with IPv6 management tools). Check running processes: ps aux | grep net6. Check open network listeners: netstat -tulpn | grep -i net6 or ss -tulpnAffected if a net6-based service is listening on a network interface and accepting remote connections
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Check for connection handling without limitsReview service configuration for connection rate limiting or max connections settings. Check if the service has any throttling: grep -r "max" /etc/net6/ or look in the service configuration files. Monitor for unusually high connection countsAffected if the service accepts connections without apparent rate limiting or maximum connection constraints, allowing a large number of connections to be made
The system is affected if libnet6 version 1.3.13 or earlier is installed AND a network service using libnet6 is exposed to accept remote connections without proper connection limits, allowing an attacker to trigger user ID wraparound through many connections.
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 to libnet6 version 1.3.14 or later. If upgrade is not possible, implement connection ID allocation limits and use larger integer types for connection tracking to prevent overflow.
- Consultation4.0 h
- Implementation8.0 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 $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-4093 — 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-2011-4093 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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