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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2012-5370
• https://bugzilla.redhat.com/show_bug.cgi?id=880671
• http://rhn.redhat.com/errata/RHSA-2013-0533.html
• jruby/jruby@5e4aab2
• http://jruby.org/2012/12/03/jruby-1-7-1