CVE-2012-5371

Ruby (aka CRuby) 1.9 before 1.9.3-p327 and 2.0 before r37575 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 a variant of the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4815.

Published: 2012-11-28 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2012-5371 is rated Moderate Risk (51.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.36%). EPSS rose +1.42% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2012-5371

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.94% 3.36% +1.42%
2 2026-06-04 1.48% 1.94% +0.46%
3 2026-06-03 — 1.48% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2012-5371

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2012-5371

OS Trackers for CVE-2012-5371

vendor priority summary link
gentoo normal CVE-2012-5371: 1 GLSA(s) (201412-27), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2012-5371
redhat medium — https://access.redhat.com/security/cve/CVE-2012-5371
ubuntu low CVE-2012-5371 low priority: Ubuntu including 2 source packages (ruby1.8, ruby1.9.1), 16 status rows across 8 suites (hardy, lucid, oneiric, precise, quantal, raring, saucy, upstream): not-affected 7, released 5, ignored 3, DNE 1. https://ubuntu.com/security/CVE-2012-5371

Affected software / configurations for CVE-2012-5371

Vendor Product Version Raw CPE
ruby-lang ruby <= 1.9.3 cpe:2.3:a:ruby-lang:ruby:*:p286:*:*:*:*:*:*
ruby-lang ruby 1.9 cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:*:*:*:*:*:*:*
ruby-lang ruby 1.9.2 cpe:2.3:a:ruby-lang:ruby:1.9.2:*:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:*:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p0:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p125:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p194:*:*:*:*:*:*
ruby-lang ruby 2.0 cpe:2.3:a:ruby-lang:ruby:2.0:*:*:*:*:*:*:*

References for CVE-2012-5371

cvelogic Threat Intelligence