Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 28 Feb 2023 19:55:43 -0600
From: John Helmert III <>
Subject: Re: sudo: double free with per-command chroot sudoers

Has a CVE been requeested?

On Tue, Feb 28, 2023 at 07:31:11AM -0700, Todd C. Miller wrote:
> A flaw exists in sudo's per-command chroot feature that could result
> in the variable that stores the command being freed more than once.
> I believe this is a fairly low-impact bug as the per-command chroot
> feature is not widely used.  The bug was caught by glibc's double-free
> detection while I was performing some chroot-related testing.  No
> one else has reported the bug which leads me to believe it probably
> has not been encountered in the wild.
> Sudo versions affected:
>     Sudo versions 1.9.8 through 1.9.13p1 inclusive are affected.
>     Versions of sudo prior to 1.9.8 are not affected.
> Details:
>     Starting with Sudo 1.9.3, it is possible to specify an alternate
>     root directory that sudo will change to before executing the
>     command.  For example:
> 	someuser ALL = CHROOT=/var/www /bin/sh
>     will result in /bin/sh being run inside the chroot jail /var/www
>     when the specific user runs "sudo sh".
>     Sudo 1.9.8 included a fix for a memory leak in the set_cmnd_path()
>     function which can result in the "user_cmnd" variable being
>     freed twice, but only when processing a sudoers rule that
>     contains a "CHROOT" setting.  This does not affect the "chroot"
>     Defaults setting.  Only a per-rule "CHROOT" setting will trigger
>     the bug.
> Impact:
>     The bug can only be triggered by a user that has been granted
>     sudo privileges using a sudoers rule that contain a "CHROOT"
>     setting and the rule must match the current host.  If no users
>     have sudoers rules containing "CHROOT" there is no impact.  This
>     feature is not commonly used.
> Workaround:
>     Remove rules from the sudoers file than contain a "CHROOT"
>     setting if using an affected version of sudo.
> Fix:
>     The bug is fixed in sudo 1.9.13p2.

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)

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.