CVE-2012-6051
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 · uneditedGoogle CityHash computes hash values without properly restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table, as demonstrated by a universal multicollision attack.
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 confidenceGoogle CityHash computes hash values without properly restricting the ability to trigger hash collisions predictably, allowing context-dependent attackers to cause denial of service (CPU consumption) via crafted input to applications that maintain hash tables, demonstrated by a universal multicollision attack.
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 dataall versionsCVSS 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
- Partial
AV:N/AC:L/Au:N/C:N/I:N/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.
-
Identify CityHash library presenceSearch the system for libcityhash.so or cityhash library files: find / -name '*cityhash*' 2>/dev/null on Linux, or check installed packages for cityhash on Red Hat/CentOS/Debian systemsAffected if CityHash library files are found on the system
-
Find binaries linking to CityHashUse ldd on binaries or check /proc/*/maps for running processes: ldd /path/to/binary | grep cityhash, or grep -r cityhash /proc/*/maps 2>/dev/nullAffected if Any running application or binary is linked against CityHash
-
Review application source code for CityHash usageIf source code is available, search for cityhash includes and usage: grep -r 'cityhash' /path/to/source/code/ | grep -i includeAffected if Application code includes CityHash headers or calls CityHash functions
-
Identify hash table use casesExamine applications using CityHash to determine if hash tables are the intended use case. Check if CityHash is used for hash table key storage or lookup operations in the application logicAffected if CityHash is being used specifically for hash table operations (the vulnerable context)
-
Check for collision-aware monitoringReview application logs and system monitoring for unusual CPU spikes that correlate with specific input patterns, which may indicate collision attacksAffected if Applications using CityHash for hash tables experience unexpected CPU load spikes with crafted input
The environment is affected if any application or service uses Google CityHash for hash table operations, as all versions of CityHash are vulnerable to predictable hash collisions that can be exploited for DoS attacks.
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 dataReplace CityHash with a cryptographically secure hash function like SipHash for hash table use cases, or implement input validation and rate limiting on hash table operations to mitigate collision-based DoS attacks.
- Consultation3.0 h
- Implementation6.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-6051 — 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-2012-6051 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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