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                             Luigi Auriemma

Application:  Raydium
              http://raydium.org
Versions:     <= SVN revision 309
              (newer versions can be vulnerable to some of the bugs
              which are still unfixed)
Platforms:    Windows, *nix, *BSD and others
Bugs:         A] buffer-overflow in raydium_log and
                 raydium_console_line_add
              B] format string in raydium_log
              C] NULL function pointer in raydium_network_netcall_exec
              D] buffer-overflow and invalid memory access in
                 raydium_network_read
Exploitation: A] remote, versus server and client
              B] remote, versus server and client
              C] remote, versus server and client
              D] remote, versus client
Date:         12 May 2006
Author:       Luigi Auriemma
              e-mail: aluigi@autistici.org
              web:    aluigi.org


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1) Introduction
2) Bugs
3) The Code
4) Fix


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===============
1) Introduction
===============


Raydium is a complete open source game engine with multiplayer support
and many other important and interesting features.


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=======
2) Bugs
=======

--------------------------------------------------------------
A] buffer-overflow in raydium_log and raydium_console_line_add
--------------------------------------------------------------

The logging function of Raydium is very used in all the engine.
For example everytime a client tries to join the server it logs the
event in the console:

  raydium_log("network: client %i connected as %s"/*,inet_ntoa(from->sin_addr)*/,n,name);

This useful function is affected by a buffer-overflow bug where the
local buffer str of 255 (RAYDIUM_MAX_NAME_LEN) bytes is filled using
the unsecure sprintf function.
The size of the input packet is 512 (RAYDIUM_NETWORK_PACKET_SIZE)
bytes of which 508 are available for the text to use for exploiting the
vulnerability.

  From raydium/log.c:

// need to be secured
void raydium_log(char *format, ...)
{
char str[RAYDIUM_MAX_NAME_LEN];
va_list argptr;


va_start(argptr,format);
vsprintf(str,format,argptr);
va_end(argptr);

printf("Raydium: %s\n",str);
if(raydium_log_file) fprintf(raydium_log_file,"%s\n",str);
raydium_console_line_add(str);
}


Similar thing for raydium_console_line_add:

  From raydium/console.c:

// need to secure this one too
void raydium_console_line_add(char *format, ...)
{
char str[RAYDIUM_MAX_NAME_LEN];
va_list argptr;
va_start(argptr,format);
vsprintf(str,format,argptr);
va_end(argptr);

raydium_console_line_last++;
if(raydium_console_line_last>=RAYDIUM_CONSOLE_MAX_LINES)
   raydium_console_line_last=0;

strcpy(raydium_console_lines[raydium_console_line_last],str);
}


-------------------------------
B] format string in raydium_log
-------------------------------

The same raydium_log function described above is affected also by a
format string vulnerability caused by the calling of
raydium_console_line_add passing directly the text string without the
required format argument:

  raydium_console_line_add(str);


--------------------------------------------------------
C] NULL function pointer in raydium_network_netcall_exec
--------------------------------------------------------

The function raydium_network_netcall_exec is called by
raydium_network_read for selecting the specific function to use for
handling the type of packet received.
The raydium_network_netcall_type array is initialized with the type -1
so if the attacker uses the type 0xff the function will try to call
raydium_network_netcall_func which is still initialized with a NULL
pointer.
The effect is the crash of the program.

From raydium/network.c:

...
for(i=0;i<RAYDIUM_NETWORK_MAX_NETCALLS;i++)
    {
    raydium_network_netcall_type[i]=-1;
    raydium_network_netcall_func[i]=0;
    raydium_network_netcall_tcp[i]=0;
    }
...

void raydium_network_netcall_exec(int type,char *buff)
{
char tmpbuff[RAYDIUM_NETWORK_PACKET_SIZE];
int i;
void (*f)(int, char*);

for(i=0;i<RAYDIUM_NETWORK_MAX_NETCALLS;i++)
 if(raydium_network_netcall_type[i]==type)
 {
    memcpy(tmpbuff,buff,RAYDIUM_NETWORK_PACKET_SIZE);
    f=raydium_network_netcall_func[i];
    f(type,tmpbuff);
 }
}


--------------------------------------------------------------------
D] buffer-overflow and invalid memory access in raydium_network_read
--------------------------------------------------------------------

The function raydium_network_read is affectd by some buffer-overflow
bugs which happen during the writing of some global variables
allocated in an array of 32 (RAYDIUM_NETWORK_MAX_SERVERS) elements.
The same function is also affected by an invalid memory access could
happen when the server sends a packet to the client containing an 8
bit id bigger than 8 (RAYDIUM_NETWORK_MAX_CLIENTS).
Both the bugs can be exploited only versus the clients.

From raydium/network.c:

signed char raydium_network_read(int *id, signed char *type, char *buff)
    ...
    strcpy(raydium_network_server_list[slot].name,name);
    ...
    strcpy(raydium_network_server_list[slot].info,info);
    ...
    i=buff[RAYDIUM_NETWORK_PACKET_OFFSET];
    strcpy(raydium_network_name[i],buff+RAYDIUM_NETWORK_PACKET_OFFSET+1);
    ...


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===========
3) The Code
===========


http://aluigi.org/poc/raydiumx.zip


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======
4) Fix
======


Some of the bugs have been fixed in the current SVN and the others will
be fixed soon.


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