oss-sec mailing list archives

Re: blkid command injection


From: cve-assign () mitre org
Date: Wed, 26 Nov 2014 12:16:55 -0500 (EST)

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There is a command injection inside blkid.

Given an USB stick with /dev/sdb1 you can: ...

ID_FS_`/tmp/foo` "" UUID=...

"blkid -o udev" is often used in root context via udev or in automounters
(uam-pmount) to construct key=value environment variables inside shell scripts
which are then evaluated.

Use CVE-2014-9114.

It seems fairly clear that "blkid -o udev" is attempting to create
lines that are safe sh input. Or, more specifically, the expectation
is that the lines would be directly usable. We currently don't see a
reasonable alternative interpretation that blkid is simply attempting
to provide output lines that accurately reflect strings found on
device media, and is expecting that other components will make a
security determination about each line, before using that line as sh
input. Also, the blkid maintainer has apparently made other changes
relating to quoting of strings found on device media:

  http://git.kernel.org/cgit/utils/util-linux/util-linux.git/commit/?id=1c9885cde853a458b5abe5ce0804abc27caf4fd4

(we understand that it's not completely analogous). Finally,
http://git.kernel.org/cgit/utils/util-linux/util-linux.git/tree/misc-utils/blkid.8
says 'print key="value" pairs for easy import into the udev
environment' and those security determinations would probably not be
considered "easy import."

- -- 
CVE assignment team, MITRE CVE Numbering Authority
M/S M300
202 Burlington Road, Bedford, MA 01730 USA
[ PGP key available through http://cve.mitre.org/cve/request_id.html ]
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