Hello,
About sudo in particular.
* You can force for a prompt (5mn by default on Mac OSX,) adding a line
such as the following in /etc/sudoers (using the visudo command):
Defaults timestamp_timeout = 0
* By default users do not authenticate on a per-tty basis. You can
enforce it with the following option:
Defaults tty_tickets
The last is activated by default on GNU/Linux distro Ubuntu. The reading
of the sudoers manual page is a very interesting.
Regards,
--
Baptiste MALGUY - System Engineer EASYNET
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www.easynet.com - phone: +33 1 44 54 70 00 - fax: +33 1 44 54 70 01
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Marvin Simkin wrote:
I respectfully disagree with this proposal and maybe we should discuss it.
Being a member of the admin group is NOT 100% equal to being root. Therefore
when you switch from admin group to uid=0 you are escalating privileges. A
trojan that gets control of an admin's session should not be able to escalate
itself to root without a password prompt, which requires a human to decide
(rightly or wrongly...) yes I do want to increase the authority of this
process.
Sure, an admin should be smart enough not to get trojaned, but what if they
do anyway?
Maybe a cracker could write a trojan that esclates itself using the powers of
the admin group, but why make it easier for those who don't know how?
The myth that it should be easy for uneducated users to expose their
computers to harm is one reason why certain other GUI platforms have so many
security problems.
host:/tmp1 sysmsimkin$ id
uid=505(sysmsimkin) gid=505(sysmsimkin) groups=505(sysmsimkin),
81(appserveradm), 79(appserverusr), 80(admin)
host:/tmp1 sysmsimkin$ ls -ld /tmp1
drwxr-xr-x 3 501 admin 102 Jun 28 2006 /tmp1
host:/tmp1 sysmsimkin$ mkdir /tmp1/tmp2
mkdir: /tmp1/tmp2: Permission denied
host:/tmp1 sysmsimkin$ /usr/bin/sudo /bin/bash
Password:
host:/tmp1 root# mkdir /tmp1/tmp2
host:/tmp1 root# ls -ld /tmp1/tmp2
drwxr-xr-x 2 root admin 68 Jan 25 11:20 /tmp1/tmp2
host:/tmp1 root# exit
host:/tmp1 sysmsimkin$ rmdir /tmp1/tmp2
rmdir: /tmp1/tmp2: Permission denied
host:/tmp1 sysmsimkin$ /usr/bin/sudo /bin/bash
host:/tmp1 root# rmdir /tmp1/tmp2
host:/tmp1 root# exit
host:/tmp1 sysmsimkin$
More interesting (to me) why wasn't I prompted for a password the second
time? (Yes I know it was designed that way, I'm asking was that the right
decision.) Presumably there is a window of vulnerability for a few minutes
AFTER you have been root during which you could fall victim to a trojan.
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