Re: StarOffice 5.2 Temporary Dir Vulnerability

[Kurt Seifried <listuser () seifried org>]

[snipsnip]
> When StarOffice creates the /tmp/soffice.tmp directory (with explicitly
> set permissions 0777), it also seems to sometimes chmod() this directory
> to 0777 afterwards.  Therefore if user A were to create a symbolic link
> to any file owned by user B, and if user B were to run StarOffice the
> target of the link will become 0777.  As a result, if the directory
> containing this target is accessible by user A, they can do whatever
> they want with the target file.  Some trivially exploitable scenarios
> here include:

[snipsnip]
> My suggested workaround is to create a symbolic link from
> /tmp/soffice.tmp to a directory inside the your home directory which
> is inaccessible to anyone but yourself. Doing this before running
> StarOffice would seem to protect against the vulnerability and this
> could be written into a simple shell script wrapper.
> Regards,
>
> Christian.

On my machines /tmp is mounted noexec, so when I tried to install StarOffice 5.2
it failed (it copies files into /tmp and then execs them). Rather then remount
my /tmp I did the following:
mkdir ~/tmp
export TMP="$HOME/tmp"
Then tried to install. I almost fell off my chair when StarOffice installed
properly, it honors $TMP (I can count on my hand how many commercial programs
honor $TMP). Instead of mucking about with /tmp permissions it might be a whole
lot simpler to chuck a tmp dir into etcskel (and all existing user's dirs) and a
$TMP definition into the various shell config files (i.e. /etc/profile). I
believe Mandrake does this now (they told me they'd do it, I haven't actually
checked the latest release).

Kurt Seifried - seifried () securityportal com
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