[Full-Disclosure] Mozilla Thunderbird 0.8 / Firefox 0.9.3 temporary files (local)

[Martin <broadcast@xxxxxxxxxxx>]

Advisory attached.
Mozilla Thunderbird 0.8 / Firefox 0.9.3 temporary files (local)

Martin (broadcast@xxxxxxxxxxx)

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Program Description
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"Thunderbird, our latest email program, includes intelligent spam 
filters, spell-checking, security, customization, and newsgroups 
support."

www.mozilla.org

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Problem Description
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When opening an attachment, or a link included in an email, Thunderbird 
prompts the user with a dialog box, giving the choice to "Save to Disk" 
or to "Open with" <default program>.

For example, we receive a PDF document attached, and on the Attachments 
section, we choose "Open". 

broadcast:/tmp$ ls -l *.pdf
-rw-------  1 broadcast broadcast 2002560 2004-10-24 18:38 wskbq43m.pdf

While the dialog box is still open, the file permissions are OK, and the 
filename is random (except for the extension). 
If we choose to save it to disk, and check /tmp again:

broadcast:/tmp$ ls -l *.pdf
ls: *.pdf: No such file or directory

Great, it's gone. Now let's choose to open it with the default viewer 
(in my case, xpdf).
Again, while the dialog box is open, there are no apparent problems.

broadcast:/tmp$ ls -l *.pdf
-rw-------  1 broadcast broadcast 2002560 2004-10-24 18:42 hp1h30si.pd

But after choosing to open it with xpdf:

broadcast:/tmp$ ls -l *.pdf
-rw-r--r--  1 broadcast broadcast 2002560 2004-10-24 18:42 programming.pdf

The file becomes world readable, until the user closes xpdf, or whatever 
application he chose to read the attachment.
Also, the filename becomes predictable, but if the filename already 
exists on /tmp, Thunderbird will choose a similar filename, and won't 
work on the existing one.

This exact issue affects Mozilla Firefox 0.9.3. I haven't tested 
older/newer versions, and all of this was tested under Debian Unstable.

A copy of this advisory and future updates on this issue may be found on:
http://broadcast.ptraced.net/advisories/008-firefox.thunderbird.txt