bugtraq - Mathematica on Linux /tmp/MathLink vulnerability

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <201005140156.o4E1uAbl021496@bari.maths.usyd.edu.au>
Date: Fri, 14 May 2010 11:56:10 +1000
From: paul.szabo@...ney.edu.au
To: bugtraq@...urityfocus.com, full-disclosure@...ts.grok.org.uk
Subject: Mathematica on Linux /tmp/MathLink vulnerability

"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@...fram.com on 7 May 2010, was assigned [TS 16194].

Cheers,

Paul Szabo   psz@...hs.usyd.edu.au   http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics   University of Sydney    Australia