After pointing out the X.Org security issues publicly this morning, Alan Coopersmith noted a presentation done by Ilja van Sprundel, the developer that uncovered these issues and is the Director of Penetration Testing at IOActive. The presentation (74 page PPT) was presented at CanSecWest about the Linux desktop security.
Sprundel formerly used Linux full-time but for the past several years converted back to Windows for business reasons and has just been a sporadic Linux user until his recent evaluation atop Ubuntu Linux, among other distributions.
Not all of the specific bugs for the multiple security vulnerabilities he discovered were disclosed, since not all of the problems have been fixed yet by their upstream projects. However, he's come across world-writable shared memory issues, world-writable scripts, bloated suid binaries, misconfigurations, and over 60 finds in total in about one week of tinkering with the Linux desktop.
Potential security holes were also uncovered in DBus and plenty of other standard Linux desktop libraries as potential attack points. Problems were also uncovered for KDE/Qt as well as GNOME/GTK+ components, including LightDM and other Xlib users. Holes are also believed to exist within package managers and the clipboard too.
While not all of the details were shared publicly, Ilja van Sprundel did recommend using dietlibc or uClibc over glibc, which he found to be "super bloated" yet the default for most Linux distributions.
Beyond feeling the Linux desktop security could be several orders of magnitude better, Ilja feels that there's really a lot of work to do that's left to address these issues. Most of the cited sited "is not written with a trust boundary in mind."