Security issue with .desktop files revisited
mike at plan99.net
Tue Mar 28 15:37:41 EEST 2006
Francois Gouget wrote:
> So in the above scenario, when the user downloads the rogue '.desktop'
> file to his desktop, that file will be tagged as 'untrusted'. Then,
> clicking on it would warn the user before running it. .desktop files
> shipped with the distribution would not have the 'untrusted' bit and
> thus would not issue this warning. Also, this warning could be
> selectively issued only for .desktop and 'executable' files, and not
> if the file is merely a simple jpeg. But that could be configurable
> and a 'paranoid' setting would warn for all untrusted files (in case
> they are designed to trigger buffer overflows).
> Such a solution requires quite a bit of work and time to be
> implemented but then I think any solution to this problem do.
Yes, this is a variant on the +x bit marks a file as trusted.
Here's an idea - the problem with requiring an EA or +x to be set is it
breaks backwards compatibility (it'd break Crossover/Wine for one ...).
But what if the logic is inverted - so the absence of +x means a file is
trusted, and web browsers or email programs set +x when they save a file
to disk? The +x bit on a .desktop file in the users home dir is then
treated as a "don't trust" marker. This doesn't break backwards
compatibility and only requires that web browsers and email programs be
I'd still be happier with some solution that prevented a .desktop file
masquerading as a JPEG file, but anything is better than nothing ...
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