Type packetstorm
Reporter xm
Modified 1999-08-17T00:00:00


                                            `Windows FAT Filesystem Advisory  
It appears that Windows' FAT file system can be messed up by creating a long enough series of recursive  
directories. After a certain point is reached, directories cannot be deleted. Because each directory added to the file  
allocation takes up a certain amount of space, this can be considered a denial of service attack against the Windows  
filesystem, allowing a user able to create directories to consume disk space. Microsoft's scandisk does not correct  
this problem (do any commercial products?). Windows cannot delete the directory, claiming it is in use. And running  
deltree against it seems to hang the system. So better lock down that anonymous ftp upload directory!   
I fired this off in 20 minutes after discovering a clever script I made messed up my filesystem. I'm sure I have  
made a few technical errors and would love corrections. I would appreciate any specific observations about behavior  
of this on various filesystems and platforms, and any workarounds or fixes found. If you find anything or just want  
to comment email xm <>. And be sure to check out our main site <>!   
Sample Code (pissy.bat)   
mkdir y  
cd y  
fatalert.shtml modified Friday, 05-Feb-1999 22:39:02 EST Copyright 1998, 1999 Geek  
Mafia and xm. They may be redistributed freely at no cost in its original form.