"If you're doing anything technical, think Mathematica --..." http://www.wolfram.com/products/mathematica/index.html Mathematica7 on Linux uses the /tmp/MathLink directory in insecure ways. Mathematica creates or re-uses an existing /tmp/MathLink directory, and overwrites files within and follows symlinks. This type of behaviour is "known unsafe" on multi-user machines e.g. University login servers. As a classic example of a symlink attack, if an "attacker" uses: mkdir /tmp/MathLink; ln -s /home/victim/.bashrc /tmp/MathLink/.gshmm then when the victim runs Mathematica his ~/.bashrc will be clobbered. New files are created world-writable, allowing a complete compromise of the user account by linking to ~/.bash_logout . (If root ever uses Mathematica then the damage is greater.) Mathematica uses also /tmp/fonts$$.conf in insecure ways. Workaround: use command-line math instead of pretty interface. Notified support@wolfram.com on 7 May 2010, was assigned [TS 16194]. Cheers, Paul Szabo psz@maths.usyd.edu.au http://www.maths.usyd.edu.au/u/psz/ School of Mathematics and Statistics University of Sydney Australia