- 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:
Thilo Schulz 2006-06-16 20:38:08 +00:00
parent c9c15562ea
commit 813a6ecdc3
2 changed files with 40 additions and 18 deletions

View file

@ -1444,13 +1444,6 @@ void CL_NextDownload(void) {
else
s = localName + strlen(localName); // point at the nul byte
// Make sure the server cannot make us write to non-quake3 directories.
if(strstr(localName, "../") || strstr(localName, "..\\"))
{
Com_Error(ERR_DROP, "CL_NextDownload: Invalid download name %s", localName);
return;
}
CL_BeginDownload( localName, remoteName );
clc.downloadRestart = qtrue;

View file

@ -2597,15 +2597,16 @@ 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;
@ -2615,6 +2616,13 @@ qboolean FS_ComparePaks( char *neededpaks, int len, qboolean dlstring ) {
continue;
}
// Make sure the server cannot make us write to non-quake3 directories.
if(strstr(fs_serverReferencedPakNames[i], "../") || strstr(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!
@ -2627,6 +2635,12 @@ 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] );
@ -2647,6 +2661,14 @@ 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
{
@ -3209,7 +3231,7 @@ 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 );
@ -3218,30 +3240,37 @@ 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 < sizeof(fs_serverReferencedPakNames) / sizeof(*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 ) {
if(d > MAX_SEARCH_PATHS)
d = MAX_SEARCH_PATHS;
}
else 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;
}
/*