[Python-Dev] Critical bash vulnerability CVE-2014-6271 may affect Python on *n*x and OSX

[Devin Jeanpierre]

On Thu, Sep 25, 2014 at 4:53 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> In other words, os.system is *already* an attack vector, unless you only
>> use it with trusted strings. I don't think the bash env vulnerability
>> adds to the attack surface.
>>
>> Have I missed something?
>
> The part where the attack payload is passed through the environment, not
> through hypothetical user-injected command-line arguments.

As I understand it, if the attacker can help specify the environment
(e.g. this is a CGI script), and you run os.system('echo hi'), you can
get pwned. Even safe uses of os.system are vulnerable unless you point
/bin/sh at a secure shell (e.g. patched bash).

-- Devin