[Bf-committers] Please turn off Auto Run Python Scripts by default

Yu Asakusa yu.asakusa at gmail.com
Tue Jun 4 12:51:14 CEST 2013


Currently “Auto Run Python Scripts” in the File tab in the user
preferences (UserPreferencesSystem.use_scripts_auto_execute in Python)
is turned on by default.  Please turn it off by default.

The current default setting means that when users open a blend file,
Blender runs any Python scripts in the file as long as they are marked
for auto-run.  Python scripts can read/write local files and do other
malicious things.  Therefore, if users would like to open an untrusted
blend file, they must explicitly disable auto-run by either turning
off “Auto Run Python Scripts” in the user preferences or turning off
the “Trusted Source” checkbox in the File Browser window.  (See also
my post on Google+

I do not think many users know it is dangerous to open an untrusted
blend file with the default settings in Blender.  It is different from
the common expectation for file-editing programs such as word
processors: opening an untrusted file in file-editing programs is
usually not considered to be a security risk.  In other words, in
file-editing programs, it is program’s responsibility to prevent
attacks even if users open malicious files.  Depending on the point of
view, the current default behavior may be considered as a security
vulnerability in Blender because of the mismatch between user’s
expectation and the actual behavior.


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