The g_file_copy function in glib 2.0 sets the permissions of a target file to the permissions of a symbolic link (777), which allows user-assisted local users to modify files of other users, as demonstrated by using Nautilus to modify the permissions of the user home directory.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-3289
• https://bugs.launchpad.net/ubuntu/+source/glib2.0/+bug/418135
• https://bugzilla.gnome.org/show_bug.cgi?id=593406
• http://lists.opensuse.org/opensuse-security-announce/2010-04/msg00006.html
• http://secunia.com/advisories/39656
• http://www.openwall.com/lists/oss-security/2009/09/08/8
• http://www.vupen.com/english/advisories/2010/1001