Re: Possible issue: XXE (Xml eXternal Entity) attack

Chris Lilley wrote,
> MS> ... but in at least some cases the very act of attempting
> MS> validation will trigger the dangerous behaviour, eg. retrieving an
> MS> uncached DTD external subset.
>
> Okay. Although, accepting the original XML message (if its a
> protocol, say) might be just as dangerous.

Agreed.

Which is why this is a delicate area where guidance is needed: if it 
seems like you're damned if you do and you're damned if you don't, then 
you're likely to toss a coin and hope for the best.

> MS> Representation retrieval is safe: Agents do not incur obligations
> MS> by retrieving a representation.
>
> Aha. Thanks for being more specific as to the link between the
> security alert you posted and the edits to the Arch doc that should
> result from your input.

Sorry ... I didn't make it anything like clear enough.

Cheers,


Miles