ftpd security issue ?

[Eugene Grosbein]

09.12.2011 19:24, gabor at zahemszky.hu пишет:
>  On Fri, 09 Dec 2011 15:39:15 +0700, Eugene Grosbein wrote:
>> 09.12.2011 15:25, Xin LI пишет:
>>> On Fri, Dec 9, 2011 at 12:04 AM,  <gabor at zahemszky.hu> wrote:
>>>> Hi!
>>>>
>>>> Are the following steps enough to prevent me?
>>>>
>>>> # for user in user1 user2 .... ; do
>>>> mkdir -p ~$user/lib ~$user/usr/lib ~$user/etc
>>>> chflags sunlink,schg ~$user/lib ~$user/usr ~$user/usr/lib 
>>>> ~$user/etc
>>>> done
>>>> #
>>>
>>> Yes that should be sufficient workaround.
>>
>> Why /lib and /usr/lib only?
> 
>  ??? /lib, /usr/lib and /etc.
> 
>  Which directory is missing?

I do not know and therefore, ask.
What guarantees that no other directory may be used to load a library from?

Eugene Grosbein