Heap-based buffer overflow in the rb_str_justify function in string.c in Ruby 1.9.1 before 1.9.1-p376 allows context-dependent attackers to execute arbitrary code via unspecified vectors involving (1) String#ljust, (2) String#center, or (3) String#rjust. NOTE: some of these details are obtained from third party information.
https://exchange.xforce.ibmcloud.com/vulnerabilities/54674
http://www.vupen.com/english/advisories/2009/3471
http://www.securityfocus.com/bid/37278
http://www.ruby-lang.org/en/news/2009/12/07/heap-overflow-in-string/