[Secure-testing-team] Bug#612035: vulnerability: rewrite arbitrary user file

[Kees Cook]

Package: feh
Version: 1.10-1
Severity: grave
Tags: security
Justification: user security hole
User: ubuntu-devel at lists.ubuntu.com
Usertags: origin-ubuntu natty

This bug report was also filed in Ubuntu and can be found at
http://launchpad.net/bugs/607328
The description, from segooon, follows:

Binary package hint: feh

Hi, I've just discovered that feh is vulnerable to rewriting any user file:

      tmpname_timestamper =
         estrjoin("", "/tmp/feh_", cppid, "_", basename, NULL);
....
            execlp("wget", "wget", "-N", "-O", tmpname_timestamper, newurl,
                   quiet, (char*) NULL);

If attacker knows PID of feh and knows the URL, it can create the link to any user file. wget would overwrite it.

Thanks.

-- System Information:
Debian Release: squeeze/sid
  APT prefers natty
  APT policy: (500, 'natty')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.37-12-generic (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash