####################################################################### Application: KpyM telnet server v1.05 for Windows NT/2000/XP Url: http://kpym.sourceforge.net/ Versions: <= 1.05 Platforms: Windows Bug: Socket flood bug Risk: High Exploitation: Remote Date: 3 Gen 2004 Author: NoRpiUs e-mail: norpius@altervista.org web: http://norpius.altervista.org ####################################################################### 1) Introduction 2) Bug 3) The Code 4) Fix 5) Screenshoot ####################################################################### ======================= 1) Introduction ======================= KpyM telnet server is a good tool that open the famous login port, like the name says. It is written by Kroum Grigorov. Here you can find the v1.05: http://norpius.altervista.org/Kts105.exe I tell you this because on the main site now there is the v1.06. ======================= 2) Bug ======================= The connection was marked free before all the components(sockets/threads etc) were shut down. When there are few connections it is not noticible since before a new connection arrives the old one is already free but with a lot of connections the server crashes. ======================= 3) The code ======================= Here you can find the source .c and the binary file. http://norpius.altervista.org/kpym.zip ======================= 4) Fix ======================= The new version that fixed this bug has already released. ======================= 5) Screenshoot ======================= C:\lcc\bin>kpym 80.116.180.23 KpyM Telnet Server v1.05 DoS by NoRpiUs e-mail: norpius@altervista.org web: http://norpius.altervista.org [+] Connecting to 80.116.180.23:23... [+] Waiting for the crash........................................................... ................................................................................ .. [+] Crashed C:\lcc\bin>