FreeBSD Security Advisories
2019-Jul-24 13:48 UTC
FreeBSD Security Advisory FreeBSD-SA-19:14.freebsd32
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============================================================================FreeBSD-SA-19:14.freebsd32
Security Advisory
The FreeBSD Project
Topic: Kernel memory disclosure in freebsd32_ioctl
Category: core
Module: kernel
Announced: 2019-07-24
Credits: Ilja van Sprundel, IOActive
Affects: FreeBSD 11.2 and FreeBSD 11.3
Corrected: 2019-07-22 18:14:34 UTC (stable/11, 11.2-STABLE)
2019-07-24 12:54:10 UTC (releng/11.2, 11.2-RELEASE-p12)
2019-07-24 12:54:10 UTC (releng/11.3, 11.3-RELEASE-p1)
CVE Name: CVE-2019-5605
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.
I. Background
The FreeBSD kernel supports executing 32-bit applications on a 64-bit
kernel, including the ioctl(2) interface.
II. Problem Description
Due to insufficient initialization of memory copied to userland in the
components listed above small amounts of kernel memory may be disclosed
to userland processes.
III. Impact
A user who can invoke 32-bit FreeBSD ioctls may be able to read the
contents of small portions of kernel memory.
Such memory might contain sensitive information, such as portions of the
file cache or terminal buffers. This information might be directly
useful, or it might be leveraged to obtain elevated privileges in some
way; for example, a terminal buffer might include a user-entered
password.
IV. Workaround
No workaround is available.
V. Solution
Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.
Perform one of the following:
1) To update your vulnerable system via a binary patch:
Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:
# freebsd-update fetch
# freebsd-update install
# shutdown -r +10min "Security update"
2) To update your vulnerable system via a source code patch:
The following patches have been verified to apply to the applicable
FreeBSD release branches.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
# fetch https://security.FreeBSD.org/patches/SA-19:14/freebsd32.patch
# fetch https://security.FreeBSD.org/patches/SA-19:14/freebsd32.patch.asc
# gpg --verify freebsd32.patch.asc
b) Apply the patch. Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile your kernel as described in
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
system.
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- -------------------------------------------------------------------------
stable/11/ r350217
releng/11.2/ r350283
releng/11.3/ r350283
- -------------------------------------------------------------------------
Note: This issue was addressed in a different way prior to the branch point
for stable/12. As such, no patch is needed for FreeBSD 12.x.
To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
Or visit the following URL, replacing NNNNNN with the revision number:
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
VII. References
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5605>
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-19:14.freebsd32.asc>
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