questions about pkexec

[Matthew Miller]

On Fri, Dec 11, 2009 at 12:45:18PM -0500, David Zeuthen wrote:
>  LANG
>  LANGUAGE
>  LC_ALL
>  LC_MESSAGES
>  SHELL
>  TERM
> We could validate the contents of these environment variables - do you
> have any attack vectors in mind that people could abuse if we didn't? Do
> you know if su(1) and sudo(8) validates such variables?

Sudo does, in a rudimentary way. Anything in the env_check list is removed
if the value contains a % or a / character. The default list treated this
way is:

  TERM
  LINGUAS
  LC_*
  LANGUAGE
  LANG
  COLORTERM

Additionally, the following variables are kept by default:

  LOGNAME
  SHELL
  USER
  USERNAME 
  SUDO_*

and others are generally added to the list in the sudoers config file
(DISPLAY, COLORS, TZ, and more).

-- 
Matthew Miller           mattdm at mattdm.org          <http://mattdm.org/>