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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2012-5371
• https://bugzilla.redhat.com/show_bug.cgi?id=875236
• https://exchange.xforce.ibmcloud.com/vulnerabilities/79993
• https://www.131002.net/data/talks/appsec12_slides.pdf
• http://2012.appsec-forum.ch/conferences/#c17
• http://asfws12.files.wordpress.com/2012/11/asfws2012-jean_philippe_aumasson-martin_bosslet-hash_flooding_dos_reloaded.pdf
• http://secunia.com/advisories/51253
• http://securitytracker.com/id?1027747
• http://www.ocert.org/advisories/ocert-2012-001.html
• http://www.osvdb.org/87280
• http://www.ruby-lang.org/en/news/2012/11/09/ruby19-hashdos-cve-2012-5371/
• http://www.securityfocus.com/bid/56484
• http://www.ubuntu.com/usn/USN-1733-1