UnixWare 7.1.3 Open UNIX 8.0.0 UnixWare 7.1.1 : Insecure handling of procfs descriptors in UnixWare can lead to local privilege escalation.
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SCO Security Advisory
Subject: UnixWare 7.1.3 Open UNIX 8.0.0 UnixWare 7.1.1 :
Insecure handling of procfs descriptors in UnixWare can lead to local privilege
escalation.
Advisory number: CSSA-2003-SCO.32
Issue date: 2003 November 11
Cross reference: sr886899 fz528474 erg712482
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1. Problem Description
"/proc/$PID/as" Contains the address space image of process
$PID. It can be opened and accessed like any other file and
be used to manipulate the process. The process owner also
owns the "as" file whose file permission is 600.
For obvious reasons this doesn't apply to processes spawned
from setuid and setgid binaries. This protection can be bypassed by
first obtaining a descriptor to a process you own then let
that process execve() a setuid binary. execve() will replace
the process image, honor the setuid bit and the descriptor
will remain open.
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CAN-2003-0937 to this issue.
2. Vulnerable Supported Versions
System Binaries
----------------------------------------------------------------------
UnixWare 7.1.3 /etc/conf/pack.d/procfs/Driver_atup.o
/etc/conf/pack.d/procfs/Driver_mp.o
Open UNIX 8.0.0 /etc/conf/pack.d/procfs/Driver_atup.o
(aka UnixWare 7.1.2) /etc/conf/pack.d/procfs/Driver_mp.o
UnixWare 7.1.1 /etc/conf/pack.d/procfs/Driver_atup.o
/etc/conf/pack.d/procfs/Driver_mp.o
3. Solution
The proper solution is to install the latest packages.
4. UnixWare 7.1.3
4.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32
erg712482c should only be installed on: UnixWare 7.1.3
4.2 Verification
MD5 (erg712482c.Z) = 50c98884a6dcb14ccf57d71aad135045
md5 is available for download from
ftp://ftp.sco.com/pub/security/tools
4.3 Installing Fixed Binaries
Upgrade the affected binaries with the following sequence:
1. Download the erg712482c.Z file to the /tmp directory on your machine.
2. As root, uncompress the file and add the package to your system
using these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482c.Z
# pkgadd -d /tmp/erg712482c
# rm /tmp/erg712482c
Alternatively, this SLS package may be installed in quiet mode,
that is, without displaying the release notes and asking for
confirmation. To do this, use these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482c.Z
# pkgadd -qd /tmp/erg712482c all
# rm /tmp/erg712482c
3. Reboot the system after installing this package.
Removal Instructions
--------------------
1. As root, remove the package using these commands:
$ su
Password: <type your root password>
# pkgrm erg712482
2. Reboot the system after removing this package.
5. Open UNIX 8.0.0
5.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32
erg712482b should only be installed on: UnixWare 7.1.2 or Open UNIX
8.0.0
5.2 Verification
MD5 (erg712482b.Z) = 54d3568e631d4739034815537242dc0d
md5 is available for download from
ftp://ftp.sco.com/pub/security/tools
5.3 Installing Fixed Binaries
Upgrade the affected binaries with the following sequence:
1. Download the erg712482b.Z file to the /tmp directory on your machine.
2. As root, uncompress the file and add the package to your system
using these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482b.Z
# pkgadd -d /tmp/erg712482b
# rm /tmp/erg712482b
Alternatively, this SLS package may be installed in quiet mode,
that is, without displaying the release notes and asking for
confirmation. To do this, use these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482b.Z
# pkgadd -qd /tmp/erg712482b all
# rm /tmp/erg712482b
3. Reboot the system after installing this package.
Removal Instructions
--------------------
1. As root, remove the package using these commands:
$ su
Password: <type your root password>
# pkgrm erg712482
2. Reboot the system after removing this package.
6. UnixWare 7.1.1
6.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32
erg712482a should only be installed on: UnixWare 7.1.1
6.2 Verification
MD5 (erg712482a.Z) = 15776bcbaf01155eb28087ee213fecf8
md5 is available for download from
ftp://ftp.sco.com/pub/security/tools
6.3 Installing Fixed Binaries
Upgrade the affected binaries with the following sequence:
erg712482a should only be installed on: UnixWare 7.1.1
1. Download the erg712482a.Z file to the /tmp directory on your machine.
2. As root, uncompress the file and add the package to your system
using these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482a.Z
# pkgadd -d /tmp/erg712482a
# rm /tmp/erg712482a
Alternatively, this SLS package may be installed in quiet mode,
that is, without displaying the release notes and asking for
confirmation. To do this, use these commands:
$ su
Password: <type your root password>
# uncompress /tmp/erg712482a.Z
# pkgadd -qd /tmp/erg712482a all
# rm /tmp/erg712482a
3. Reboot the system after installing this package.
Removal Instructions
--------------------
1. As root, remove the package using these commands:
$ su
Password: <type your root password>
# pkgrm erg712482
2. Reboot the system after removing this package.
7. References
Specific references for this advisory:
http://www.texonet.com/advisories/TEXONET-20031024.txt
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0937
SCO security resources:
http://www.sco.com/support/security/index.html
This security fix closes SCO incidents sr886899 fz528474
erg712482.
8. Disclaimer
SCO is not responsible for the misuse of any of the information
we provide on this website and/or through our security
advisories. Our advisories are a service to our customers
intended to promote secure installation and use of SCO
products.
9. Acknowledgments
SCO would like to thank Joel Soderberg and Christer Oberg
from Texonet. Texonet is a Swedish based security company
with a focus on penetration testing / security assessments,
research and development.
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