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JrubyApplication

CVE-2012-5370

MEDIUM · 5.0 CVSS v2.0 Published 2012-11-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
JRuby 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 against the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4838.

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 confidence

JRuby's MurmurHash2 implementation allows attackers to predictably trigger hash collisions via crafted input (universal multicollision attack), causing hash tables to degrade to O(n) performance and resulting in CPU exhaustion.

MitigationUpgrade JRuby to a version with hash randomization or implement input validation/rate limiting to detect and block collision-inducing payloads.

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
JrubyApplication
Affected:all versions

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm JRuby is installed
    Run 'jruby --version' or check for the jruby binary in the system PATH
    Affected if JRuby is not present on the system
  2. Determine JRuby version
    Execute 'jruby --version' and note the version number returned
    Affected if Any version of JRuby is installed (this CVE affects all JRuby versions)
  3. Identify hash collection usage
    Audit application source code for use of Ruby's Hash class or Java's HashMap that process external input
    Affected if Application uses hash-based collections to store or look up user-supplied data
  4. Check for input validation
    Review application code for validation or rate-limiting on input that could be used as hash keys
    Affected if No input validation or length limits exist on data processed by hash collections

If JRuby is installed and processes untrusted input through hash-based collections without input validation, the environment is vulnerable to hash collision attacks causing CPU exhaustion

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade JRuby to a version with hash randomization or implement input validation/rate limiting to detect and block collision-inducing payloads.

Fix this in Jruby Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing6.0 h
  • Review / QA2.0 h
17.0 hours of engineering $2,940
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2012-5370 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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