Multiple integer signedness errors in (1) UltraVNC 1.0.2 and 1.0.5 and (2) TightVnc 1.3.9 allow remote VNC servers to cause a denial of service (heap corruption and application crash) or possibly execute arbitrary code via a large length value in a message, related to the (a) ClientConnection::CheckBufferSize and (b) ClientConnection::CheckFileZipBufferSize functions in ClientConnection.cpp.
https://www.exploit-db.com/exploits/8024
https://www.exploit-db.com/exploits/7990
http://www.vupen.com/english/advisories/2009/0322
http://www.vupen.com/english/advisories/2009/0321
http://www.securityfocus.com/archive/1/500632/100/0/threaded
http://vnc-tight.svn.sourceforge.net/viewvc/vnc-tight?view=rev&revision=3564