OpenServer 5.0.7 OpenServer 6.0.0 : UnZip File Permissions Change Vulnerability
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SCO Security Advisory
Subject: OpenServer 5.0.7 OpenServer 6.0.0 : UnZip File
Permissions Change Vulnerability
Advisory number: SCOSA-2005.39
Issue date: 2005 September 28
Cross reference: sr894724 fz532853 erg712904
sr894723 fz532852 erg712905
CAN-2005-2475
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1. Problem Description
A vulnerability in unzip can be exploited by malicious,
local users to perform certain actions on a vulnerable
system with escalated privileges. The vulnerability is
caused due a race condition that exists when the uncompressed
file is closed and before its permissions are changed. This
can be exploited via hardlink attacks to change the permissions
of other files belonging to the user running unzip. Successful
exploitation requires that the malicious user is able to
delete the uncompressed file and replace it with a hardlink
to another file owned by the unzip user, before permissions
are set on the file.
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CAN-2005-2475 to this issue.
2. Vulnerable Supported Versions
System Binaries
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OpenServer 5.0.7 unzip distribution
OpenServer 6.0.0 unzip distribution
3. Solution
The proper solution is to install the latest packages.
4. OpenServer 5.0.7
4.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2005.39/507
4.2 Verification
MD5 (VOL.000.000) = d57b8a54b9547bef09ba1f25dbd2cbf1
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 VOL* files to a directory
2) Run the custom command, specify an install from media
images, and specify the directory as the location of the
images.
5. OpenServer 6.0.0
5.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2005.39/600
5.2 Verification
MD5 (VOL.000.000) = f31e45c91c87409f487613fdc5c2fb01
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 VOL* files to a directory
2) Run the custom command, specify an install from media
images, and specify the directory as the location of the
images.
6. References
Specific references for this advisory:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-2475
http://marc.theaimsgroup.com/?l=bugtraq&m=112300046224117&w=2
http://www.securityfocus.com/bid/14450
http://www.osvdb.org/18530
http://secunia.com/advisories/16309
SCO security resources:
http://www.sco.com/support/security/index.html
SCO security advisories via email
http://www.sco.com/support/forums/security.html
This security fix closes SCO incidents sr894724 fz532853
erg712904 sr894723 fz532852 erg712905.
7. 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.
8. Acknowledgments
SCO would like to thank Imran Ghory for discovering this
weakness.
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