Re: AppArmor FAQ

David Wagner
2007-04-19T16:42:42Z

James Morris wrote:
>On Wed, 18 Apr 2007, Crispin Cowan wrote:
>> How is it that you think a buffer overflow in httpd could allow an
>> attacker to break out of an AppArmor profile?
>
>Because you can change the behavior of the application and then bypass
>policy entirely by utilizing any mechanism other than direct filesystem
>access: IPC, shared memory, Unix domain sockets, local IP networking,
>remote networking etc.

Any halfway decent jail will let you control access to all of those
things, thereby preventing an 0wned httpd from breaking out of the jail.
(For instance, Janus did. So does Systrace.)

Are you saying AppArmor does not allow that kind of control? Specifics
would be useful.

>Also worth noting here is that you have to consider any limited
>environment as enforcing security policy, and thus its configuration
>becomes an additional component of security policy.

I don't understand what you are saying. Yes, the AppArmor policy
file is part of policy. Is that what you mean?