SecurityTracker.com
    Home    |    View Topics    |    Search    |    Contact Us    |   

SecurityTracker
Archives


 


Category:   OS (UNIX)  >   FreeBSD Kernel Vendors:   FreeBSD
FreeBSD UNIX-Domain Socket Buffer Overflow Lets Local Users Gain Elevated Privileges
SecurityTracker Alert ID:  1026106
SecurityTracker URL:  http://securitytracker.com/id/1026106
CVE Reference:   CVE-2011-4062   (Links to External Site)
Updated:  Oct 19 2011
Original Entry Date:  Sep 28 2011
Impact:   Denial of service via local system, Execution of arbitrary code via local system, Root access via local system
Fix Available:  Yes  Vendor Confirmed:  Yes  
Version(s): 7.3, 7.4, 8.1, 8.2, 9.0-RC1
Description:   A vulnerability was reported in FreeBSD. A local user can obtain elevated privileges on the target system. A local user can cause denial of service conditions.

A local user can supply a specially crafted address value when opening a UNIX-domain socket via the bind(2) call to cause a buffer overflow when the address is later processed by other system calls. A local user can exploit this to crash the kernel, escape a jail, or execute arbitrary code on the target system with root privileges.

Mateusz Guzik reported this vulnerability.

Impact:   A local user can cause the kernel to crash.

A local user obtain root privileges on the target system.

Solution:   The vendor has issued a fix and has provided the following solution instructions [quoted]:

Perform one of the following:

1) Upgrade your vulnerable system to 7-STABLE or 8-STABLE, or to
the RELENG_8_2, RELENG_8_1, RELENG_7_4, or RELENG_7_3 security
branch dated after the correction date.

2) To update your vulnerable system via a source code patch:

The following patch has been verified to apply to FreeBSD 7.4, 7.3,
8.2 and 8.1 systems.

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

# fetch http://security.FreeBSD.org/patches/SA-11:05/unix.patch
# fetch http://security.FreeBSD.org/patches/SA-11:05/unix.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.

3) To update your vulnerable system via a binary patch:

Systems running 7.4-RELEASE, 7.3-RELEASE, 8.2-RELEASE, or 8.1-RELEASE on
the i386 or amd64 platforms can be updated via the freebsd-update(8)
utility:

# freebsd-update fetch
# freebsd-update install

The vendor's advisory is available at:

http://security.FreeBSD.org/advisories/FreeBSD-SA-11:05.unix.asc

Vendor URL:  security.FreeBSD.org/advisories/FreeBSD-SA-11:05.unix.asc (Links to External Site)
Cause:   Boundary error

Message History:   None.


 Source Message Contents

Subject:  FreeBSD Security Advisory FreeBSD-SA-11:05.unix

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=============================================================================
FreeBSD-SA-11:05.unix                                       Security Advisory
                                                          The FreeBSD Project

Topic:          Buffer overflow in handling of UNIX socket addresses

Category:       core
Module:         kern
Announced:      2011-09-28
Credits:        Mateusz Guzik
Affects:        All supported versions of FreeBSD.
Corrected:      2011-09-28 08:47:17 UTC (RELENG_7, 7.4-STABLE)
                2011-09-28 08:47:17 UTC (RELENG_7_4, 7.4-RELEASE-p3)
                2011-09-28 08:47:17 UTC (RELENG_7_3, 7.3-RELEASE-p7)
                2011-09-28 08:47:17 UTC (RELENG_8, 8.2-STABLE)
                2011-09-28 08:47:17 UTC (RELENG_8_2, 8.2-RELEASE-p3)
                2011-09-28 08:47:17 UTC (RELENG_8_1, 8.1-RELEASE-p5)
                2011-09-28 08:47:17 UTC (RELENG_9, 9.0-RC1)

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

UNIX-domain sockets, also known as "local" sockets, are a mechanism for
interprocess communication.  They are similar to Internet sockets (and
utilize the same system calls) but instead of relying on IP addresses
and port numbers, UNIX-domain sockets have addresses in the local file
system address space.

II.  Problem Description

When a UNIX-domain socket is attached to a location using the bind(2)
system call, the length of the provided path is not validated.  Later,
when this address was returned via other system calls, it is copied into
a fixed-length buffer.

III. Impact

A local user can cause the FreeBSD kernel to panic.  It may also be
possible to execute code with elevated privileges ("gain root"), escape
from a jail, or to bypass security mechanisms in other ways.

IV.  Workaround

No workaround is available, but systems without untrusted local users
are not vulnerable.

V.   Solution

Perform one of the following:

1) Upgrade your vulnerable system to 7-STABLE or 8-STABLE, or to
the RELENG_8_2, RELENG_8_1, RELENG_7_4, or RELENG_7_3 security
branch dated after the correction date.

2) To update your vulnerable system via a source code patch:

The following patch has been verified to apply to FreeBSD 7.4, 7.3,
8.2 and 8.1 systems.

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

# fetch http://security.FreeBSD.org/patches/SA-11:05/unix.patch
# fetch http://security.FreeBSD.org/patches/SA-11:05/unix.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.

3) To update your vulnerable system via a binary patch:

Systems running 7.4-RELEASE, 7.3-RELEASE, 8.2-RELEASE, or 8.1-RELEASE on
the i386 or amd64 platforms can be updated via the freebsd-update(8)
utility:

# freebsd-update fetch
# freebsd-update install

VI.  Correction details

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

CVS:

Branch                                                           Revision
  Path
- -------------------------------------------------------------------------
RELENG_7
  src/sys/kern/uipc_usrreq.c                                   1.206.2.13
RELENG_7_4
  src/UPDATING                                             1.507.2.36.2.5
  src/sys/conf/newvers.sh                                   1.72.2.18.2.8
  src/sys/kern/uipc_usrreq.c                               1.206.2.11.4.2
RELENG_7_3
  src/UPDATING                                             1.507.2.34.2.9
  src/sys/conf/newvers.sh                                  1.72.2.16.2.11
  src/sys/kern/uipc_usrreq.c                               1.206.2.11.2.2
RELENG_8
  src/sys/kern/uipc_usrreq.c                                    1.233.2.6
RELENG_8_2
  src/UPDATING                                             1.632.2.19.2.5
  src/sys/conf/newvers.sh                                   1.83.2.12.2.8
  src/sys/kern/uipc_usrreq.c                                1.233.2.2.2.2
RELENG_8_1
  src/UPDATING                                             1.632.2.14.2.8
  src/sys/conf/newvers.sh                                   1.83.2.10.2.9
  src/sys/kern/uipc_usrreq.c                                1.233.2.1.4.2
RELENG_9
  src/sys/kern/uipc_usrreq.c                                    1.244.2.2
- -------------------------------------------------------------------------

Subversion:

Branch/path                                                      Revision
- -------------------------------------------------------------------------
stable/7/                                                         r225827
releng/7.4/                                                       r225827
releng/7.3/                                                       r225827
stable/8/                                                         r225827
releng/8.2/                                                       r225827
releng/8.1/                                                       r225827
stable/9/                                                         r225827
- -------------------------------------------------------------------------

The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-11:05.unix.asc
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (FreeBSD)

iEYEARECAAYFAk6C4nUACgkQFdaIBMps37J5lwCgnq8BUBWckn0ZKMcsK5IDKMDV
ocgAn0PwSvoKxjGY4dgHlM1M6xVM8OWz
=AO92
-----END PGP SIGNATURE-----
_______________________________________________
freebsd-security-notifications@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications
To unsubscribe, send any mail to "freebsd-security-notifications-unsubscribe@freebsd.org"
 
 


Go to the Top of This SecurityTracker Archive Page





Home   |    View Topics   |    Search   |    Contact Us

This web site uses cookies for web analytics. Learn More

Copyright 2021, SecurityGlobal.net LLC