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FreeBSD Security Advisory FreeBSD-SA-08:13.protosw

Posted on 22 December 2008
FreeBSD security notificat

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=============================================================================
FreeBSD-SA-08:13.protosw Security Advisory
The FreeBSD Project

Topic: netgraph / bluetooth privilege escalation

Category: core
Module: sys_kern
Announced: 2008-12-23
Credits: Christer Oberg
Affects: All FreeBSD releases
Corrected: 2008-12-23 01:23:09 UTC (RELENG_7, 7.1-PRERELEASE)
2008-12-23 01:23:09 UTC (RELENG_7_1, 7.1-RC2)
2008-12-23 01:23:09 UTC (RELENG_7_0, 7.0-RELEASE-p7)
2008-12-23 01:23:09 UTC (RELENG_6, 6.4-STABLE)
2008-12-23 01:23:09 UTC (RELENG_6_4, 6.4-RELEASE-p1)
2008-12-23 01:23:09 UTC (RELENG_6_3, 6.3-RELEASE-p7)

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:http://security.FreeBSD.org/>.

I. Background

The FreeBSD kernel provides support for a variety of different types of
communications sockets, including IPv4, IPv6, ISDN, ATM, routing protocol,
link-layer, netgraph(4), and bluetooth sockets. As an early form of
object-oriented design, much of the functionality specific to different
types of sockets is abstracted via function pointers.

II. Problem Description

Some function pointers for netgraph and bluetooth sockets are not
properly initialized.

III. Impact

A local user can cause the FreeBSD kernel to execute arbitrary code.
This could be used by an attacker directly; or it could be used to gain
root privilege or to escape from a jail.

IV. Workaround

No workaround is available, but systems without local untrusted users
are not vulnerable. Furthermore, systems are not vulnerable if they
have neither the ng_socket nor ng_bluetooth kernel modules loaded or
compiled into the kernel.

Systems with the security.jail.socket_unixiproute_only sysctl set to
1 (the default) are only vulnerable if they have local untrusted users
outside of jails.

If the command
# kldstat -v | grep ng_
produces no output, the system is not vulnerable.

V. Solution

Perform one of the following:

1) Upgrade your vulnerable system to 6-STABLE, or 7-STABLE, or to the
RELENG_7_0, RELENG_6_4, or RELENG_6_3 security branch dated after the
correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 6.3, 6.4,
and 7.0 systems.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

[FreeBSD 6.x]
# fetch http://security.FreeBSD.org/patches/SA-08:13/protosw6x.patch
# fetch http://security.FreeBSD.org/patches/SA-08:13/protosw6x.patch.asc

[FreeBSD 7.x]
# fetch http://security.FreeBSD.org/patches/SA-08:13/protosw.patch
# fetch http://security.FreeBSD.org/patches/SA-08:13/protosw.patch.asc

b) Apply the patch.

# cd /usr/src
# patch < /path/to/patch

c) Recompile your kernel as described in
<URL:http://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
system.

VI. Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

CVS:

Branch Revision
Path
- -------------------------------------------------------------------------
RELENG_6
src/sys/kern/uipc_domain.c 1.44.2.4
RELENG_6_4
src/UPDATING 1.416.2.40.2.4
src/sys/conf/newvers.sh 1.69.2.18.2.7
src/sys/kern/uipc_domain.c 1.44.2.3.6.2
RELENG_6_3
src/UPDATING 1.416.2.37.2.12
src/sys/conf/newvers.sh 1.69.2.15.2.11
src/sys/kern/uipc_domain.c 1.44.2.3.4.1
RELENG_7
src/sys/kern/uipc_domain.c 1.51.2.2
RELENG_7_1
src/UPDATING 1.507.2.13.2.2
src/sys/kern/uipc_domain.c 1.51.2.1.2.2
RELENG_7_0
src/UPDATING 1.507.2.3.2.11
src/sys/conf/newvers.sh 1.72.2.5.2.11
src/sys/kern/uipc_domain.c 1.51.4.1
- -------------------------------------------------------------------------

Subversion:

Branch/path Revision
- -------------------------------------------------------------------------
stable/6/ r186405
releng/6.4/ r186405
releng/6.3/ r186405
stable/7/ r186405
releng/7.1/ r186405
releng/7.0/ r186405
- -------------------------------------------------------------------------

VII. References

The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-08:13.protosw.asc

 

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