Cisco Security Advisory
Cisco Network Admission Control Guest Server System Software Authentication Bypass Vulnerability
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Cisco Network Admission Control (NAC) Guest Server system software contains a vulnerability in the RADIUS authentication software that may allow an unauthenticated user to access the protected network.
Cisco has released software updates that address this vulnerability.
This advisory is posted at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110330-nac.
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Cisco NAC Guest Server provides guest policy enforcement to Cisco NAC appliances and Cisco Wireless LAN Controllers, where guest policies are enforced.
Vulnerable Products
This vulnerability affects all versions of NAC Guest Server software prior to software version 2.0.3. The software version is displayed on the login page of the web server.
Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by this vulnerability.
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The Cisco NAC Guest Server system software contains a vulnerability in the configuration file of the RADIUS authentication software. This misconfiguration may allow an unauthenticated user to access the protected network. This vulnerability may result in authentication bypass without requiring a valid username or password.
This vulnerability is documented in Cisco Bug ID CSCtj66922 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2011-0963.
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It is possible to modify the RADIUS configuration file of the Cisco NAC Guest Access Server to eliminate thepotential for authentication bypass. The following commands modify the RADIUS configuration line file and restart the RADIUS daemon to read the new configuration file.
The configuration file may be modified by running the following command from the command-line interface (CLI) of the device:
# cp /etc/raddb/radiusd.conf /etc/raddb/radiusd.conf.orig # sed -i 's/php -f/php/g' /etc/raddb/radiusd.conf # service radiusd restart
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When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.
In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance.
Software versions prior to 2.0.3 are affected by this vulnerability. Fixed software and workarounds are available for all NAC Guest Server devices.
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The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Show LessRevision 1.0
2011-March-30
Initial public release.
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