Re: [xml-dev] Malicious XML

From
Karl Waclawek <>
To
"Anthony B. Coates" <>, xml-dev <>
Date
2002-11-15T01:52:44Z
ID
<001d01c28c49$b0d2c720$0207a8c0@karl>
Thread
Re: [xml-dev] Malicious XML
> ** Reply to message from "Karl Waclawek" <> on Thu, 14 Nov
> 2002 16:15:41 -0500
> 
> > are there any well-known ways to protect against
> > malicious XML, e.g. XML that causes your parser
> > to eat up all memory?
> 
> Disconnect your machine from any networks before you start parsing.

Well - we - the Expat team have just been notified of a
"security vulnerability" in Expat by a company called Sanctum,
http://www.sanctuminc.com/ .
No idea who they are, and I don't agree with their assessment,
i.e. it is not Expat's job to check memory use. That is
the memory manager's job.

Anyway, their example uses a really trivial internal subset
to bring down a SOAP server. I wonder if there are more
well known XML examples that can cause a parser to eat
up all memory.

Properly used, Expat is already equipped to handle such
situations since it allows for a pluggable memory handler.

Karl