multipart/parser.rb in Rack 1.3.x before 1.3.8 and 1.4.x before 1.4.3 allows remote attackers to cause a denial of service (memory consumption and out-of-memory error) via a long string in a Multipart HTTP packet.
https://groups.google.com/forum/#%21topic/rack-devel/7ZKPNAjgRSs
https://groups.google.com/forum/#%21topic/rack-devel/-MWPHDeGWtI
https://github.com/rack/rack/commit/f95113402b7239f225282806673e1b6424522b18
https://github.com/rack/rack/commit/548b9af2dc0059f4c0c19728624448d84de450ff
https://bugzilla.redhat.com/show_bug.cgi?id=895282
http://www.debian.org/security/2013/dsa-2783
http://rhn.redhat.com/errata/RHSA-2013-0548.html
http://rhn.redhat.com/errata/RHSA-2013-0544.html
http://lists.opensuse.org/opensuse-updates/2013-03/msg00048.html