OpenServer 6.0.0 : TCP Remote ICMP Denial Of Service Vulnerabilities
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SCO Security Advisory
Subject: OpenServer 6.0.0 : TCP Remote ICMP Denial Of Service
Vulnerabilities
Advisory number: SCOSA-2005.38
Issue date: 2005 September 22
Cross reference: sr894918 fz530661 erg712928 CAN-2004-0790 CAN-2004-0791
CAN-2004-1060
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1. Problem Description
The Internet Control Message Protocol is used to alert
hosts on a network about certain situations, and the hosts
then take automatic action to prevent network failures or
to improve transport efficiency. The RFC recommends no
security checking for in-bound ICMP messages, so long as
a related connection exists, and may potentially allow
several different Denials of Service. The following
individual attacks are reported: A blind connection-reset
attack is reported, which takes advantage of the specification
that describes that on receiving a 'hard' ICMP error, the
corresponding connection should be aborted. A remote
attacker may terminate target TCP connections and deny
service for legitimate users.
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CAN-2004-0790 to this issue.
An ICMP Source Quench
attack is reported, which exploits the specification that
a host must react to ICMP Source Quench messages by slowing
transmission on the associated connection. A remote attacker
may effectively degrade performance for a legitimate
connection.
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CAN-2004-0791 to this issue.
A suitable forged ICMP PMTUD message may be used to reduce the
MTU for a given connection in a similar manner.
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CAN-2004-1060 to this issue.
2. Vulnerable Supported Versions
System Binaries
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OpenServer 6.0.0 inet driver
3. Solution
The proper solution is to install the latest packages.
4. OpenServer 6.0.0
4.1 Location of Fixed Binaries
ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2005.38
4.2 Verification
MD5 (VOL.000.000) = 8b97daeeba0c5653d1e01d589109c250
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. References
Specific references for this advisory:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0791
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-1060
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 sr894918 fz530661
erg712928.
6. 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.
7. Acknowledgments
The SCO Group would like to thank Fernando Gont for reporting
these issues.
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