|
Message-ID: <20180612113836.6flipg4zlq4fw4ue@jwilk.net> Date: Tue, 12 Jun 2018 13:38:36 +0200 From: Jakub Wilk <jwilk@...lk.net> To: oss-security@...ts.openwall.com Subject: Re: Are `su user' and/or `sudo -u user sh' considered dangerous? * Georgi Guninski <guninski@...inski.com>, 2018-06-12, 13:17: >https://j.ludost.net/blog/archives/2018/06/12/are_su_user_andor_sudo_-u_user_sh_considered_dangerous/index.html > >Per vague memory I discussed half of this with some linux crowd and >they said "won't fix" long ago. > >`su user' and `sudo -u user sh' give the user the fd of root's tty and >it is readable and writable. After closing the session, the user can >keep it and on root's tty potentially do: > >1. inject keypresses via ioctl() >and/or >2. read the output of root's tty, probably with some analogue of >tee(1). > >Is this really a concern? This class of vulnerabilities has been known since at least 2005: https://bugzilla.redhat.com/show_bug.cgi?id=173008 (CVE-2005-4890) It was last discussed on oss-security in 2017: http://seclists.org/oss-sec/2017/q2/412 >Any workarounds? For sudo, there's the "use_pty" flag. (It's not enabled by default.) -- Jakub Wilk
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.