CVE-2006-3324 arbitary file overwrite

CVE-2006-3324
The Automatic Downloading option in the id3 Quake 3 Engine and the
Icculus Quake 3 Engine (ioquake3) before revision 804 allows remote
attackers to overwrite arbitrary files in the quake3 directory
(fs_homepath cvar) via a long string of filenames, as contained in the
neededpaks buffer.

Luigi Auriemma q3cfilevar

from Thilo Schulz in ioquake3
svn 804 git 813a6ecdc3b8572796a8a85b260b03e1c3d87ef4

- Fix bug that allows a malicious server to write and overwrite any
  files in the quake3 directory.  Reported by Luigi Auriemma.
- Moved directory traversal check to a more proper location.
- Added a few sanity checks for checksum/pakname storage to fix a crash
  that can occur under certain circumstances.
This commit is contained in:
Jonathan Gray 2013-05-07 15:26:25 +10:00
parent 8550620849
commit ac9e5f1f79

View file

@ -2356,15 +2356,16 @@ we are not interested in a download string format, we want something human-reada
qboolean FS_ComparePaks( char *neededpaks, int len, qboolean dlstring ) {
searchpath_t *sp;
qboolean havepak, badchecksum;
char *origpos = neededpaks;
int i;
if ( !fs_numServerReferencedPaks ) {
if (!fs_numServerReferencedPaks)
return qfalse; // Server didn't send any pack information along
}
*neededpaks = 0;
for ( i = 0 ; i < fs_numServerReferencedPaks ; i++ ) {
for ( i = 0 ; i < fs_numServerReferencedPaks ; i++ )
{
// Ok, see if we have this pak file
badchecksum = qfalse;
havepak = qfalse;
@ -2374,6 +2375,13 @@ qboolean FS_ComparePaks( char *neededpaks, int len, qboolean dlstring ) {
continue;
}
// Make sure the server cannot make us write to non-quake3 directories.
if(FS_CheckDirTraversal(fs_serverReferencedPakNames[i]))
{
Com_Printf("WARNING: Invalid download name %s\n", fs_serverReferencedPakNames[i]);
continue;
}
for ( sp = fs_searchpaths ; sp ; sp = sp->next ) {
if ( sp->pack && sp->pack->checksum == fs_serverReferencedPaks[i] ) {
havepak = qtrue; // This is it!
@ -2386,6 +2394,12 @@ qboolean FS_ComparePaks( char *neededpaks, int len, qboolean dlstring ) {
if (dlstring)
{
// We need this to make sure we won't hit the end of the buffer or the server could
// overwrite non-pk3 files on clients by writing so much crap into neededpaks that
// Q_strcat cuts off the .pk3 extension.
origpos += strlen(origpos);
// Remote name
Q_strcat( neededpaks, len, "@");
Q_strcat( neededpaks, len, fs_serverReferencedPakNames[i] );
@ -2404,6 +2418,14 @@ qboolean FS_ComparePaks( char *neededpaks, int len, qboolean dlstring ) {
Q_strcat( neededpaks, len, fs_serverReferencedPakNames[i] );
Q_strcat( neededpaks, len, ".pk3" );
}
// Find out whether it might have overflowed the buffer and don't add this file to the
// list if that is the case.
if(strlen(origpos) + (origpos - neededpaks) >= len - 1)
{
*origpos = '\0';
break;
}
}
else
{
@ -2962,7 +2984,7 @@ checksums to see if any pk3 files need to be auto-downloaded.
=====================
*/
void FS_PureServerSetReferencedPaks( const char *pakSums, const char *pakNames ) {
int i, c, d;
int i, c, d = 0;
Cmd_TokenizeString( pakSums );
@ -2971,30 +2993,35 @@ void FS_PureServerSetReferencedPaks( const char *pakSums, const char *pakNames )
c = MAX_SEARCH_PATHS;
}
fs_numServerReferencedPaks = c;
for ( i = 0 ; i < c ; i++ ) {
fs_serverReferencedPaks[i] = atoi( Cmd_Argv( i ) );
}
for ( i = 0 ; i < c ; i++ ) {
if (fs_serverReferencedPakNames[i]) {
for (i = 0 ; i < ARRAY_LEN(fs_serverReferencedPakNames); i++)
{
if (fs_serverReferencedPakNames[i])
Z_Free(fs_serverReferencedPakNames[i]);
}
fs_serverReferencedPakNames[i] = NULL;
}
if ( pakNames && *pakNames ) {
Cmd_TokenizeString( pakNames );
d = Cmd_Argc();
if ( d > MAX_SEARCH_PATHS ) {
d = MAX_SEARCH_PATHS;
}
if(d > c)
d = c;
for ( i = 0 ; i < d ; i++ ) {
fs_serverReferencedPakNames[i] = CopyString( Cmd_Argv( i ) );
}
}
// ensure that there are as many checksums as there are pak names.
if(d < c)
c = d;
fs_numServerReferencedPaks = c;
}
/*