Re: ptrace and setuid problem

[Tom Horsley <tomhorsley@adelphia.net>]

Andreas Schwab wrote:

>Tom Horsley <tomhorsley@adelphia.net> writes:
>
>  
>
>>If I exec a setuid program under ptrace, I can read the image via
>>PEEKDATA requests.
>>    
>>
>
>Only CAP_SYS_PTRACE capable processes get suid/sgid semantics under
>ptrace, or can attach to a privileged processes.
>
>Andreas.
>
>  
>
I realize the program under ptrace is no longer running setuid, but it 
is still running,
and the debugger can examine the process memory. With most setuid programs
being installed execute-only with no read access, isn't it a security 
problem that
I can get read access anyway (at least to the parts of the file that are 
in LOAD
segments)?

(Although I do notice that my suse 9.2 system has /usr/bin/sudo 
installed readable -
it is only my fedora core 3 system that has it execute only - just to 
pick a sample
setuid program).

Maybe setuid shouldn't even be the question, maybe the issue should be that
ptrace can read parts of program files that have no read access.