resources consumption in DiGi WWW Server

[Donato Ferrante]

Donato Ferrante


Application: DiGi WWW Server
http://wwwserver.sourceforge.net

Version: Compieuw.1

Bug: resources consumption

Date: 27-Apr-2004

Author: Donato Ferrante
e-mail: fdonato@autistici.org
web: www.autistici.org/fdonato



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1. Description
2. The bug
3. The code
4. The fix



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1. Description:
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Vendor's Description:

"DiGi WWW Server is a webserver. It is easy-to-use but also supports
access control, virtual folders and multiple ports. You can use plugin
dll's to add extra functionality. The server can run as a GUI
application and as an NT service."



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2. The bug:
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The program has a procedure that makes a conversion, it parses the
request strings replacing all the occurrences of slash with backslash.

So if you send to the webserver a crafted big request full of '/',
the server will be freezed by consuming a lot of CPU resources.


Furthermore it's also possible to freeze the server by sending to it a
long http request.



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3. The code:
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To test the vulnerability, send to the webserver an http request like:


GET /// [ 660 kb of / ] /// HTTP/1.1



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4. The fix:
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Bug fixed in the version Compieuw.2.



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