Mathematica Symlink Attack

Type packetstorm
Reporter Paul Szabo
Modified 2010-05-15T00:00:00


                                            `"If you're doing anything technical, think Mathematica --..."  
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 on 7 May 2010, was assigned [TS 16194].  
Paul Szabo  
School of Mathematics and Statistics University of Sydney Australia