Integer signedness error in the ssh2_rdpkt function in PuTTY before 0.56 allows remote attackers to execute arbitrary code via a SSH2_MSG_DEBUG packet with a modified stringlen parameter, which leads to a buffer overflow.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17886
http://www.securityfocus.com/bid/11549
http://www.idefense.com/application/poi/display?id=155&type=vulnerabilities&flashstatus=true
http://www.gentoo.org/security/en/glsa/glsa-200410-29.xml
http://www.chiark.greenend.org.uk/~sgtatham/putty/
http://www-1.ibm.com/support/docview.wss?uid=ssg1S1002416
http://www-1.ibm.com/support/docview.wss?uid=ssg1S1002414
http://secunia.com/advisories/17214
http://secunia.com/advisories/13012/