Microsoft ISA Server Radius OTP Authentication Bypass Vulnerability

Bugtraq ID:	35631
Class:	Failure to Handle Exceptional Conditions
CVE:	CVE-2009-1135
Remote:	Yes
Local:	No
Published:	Jul 14 2009 12:00AM
Updated:	Jul 20 2009 05:46PM
Credit:	Reported by the vendor
Vulnerable:	Microsoft ISA Server 2006 Supportability Update 0 Microsoft ISA Server 2006 SP1 Microsoft ISA Server 2006 0
Not Vulnerable:

Microsoft ISA Server Radius OTP Authentication Bypass Vulnerability

Microsoft ISA Server is prone to an authentication-bypass vulnerability.

An attacker with knowledge of a valid account name can exploit this issue to bypass authentication and gain access to arbitrary resources within the context of the selected account.

Microsoft ISA Server Radius OTP Authentication Bypass Vulnerability

Currently we are not aware of any working exploits. If you feel we are in error or if you are aware of more recent information, please mail us at: [email protected].

Microsoft ISA Server Radius OTP Authentication Bypass Vulnerability

Solution:
The vendor has released an update. Please see the references for details.


Microsoft ISA Server 2006 0

• Microsoft Security Update for ISA Server 2006 (KB 970811)
  http://www.microsoft.com/downloads/details.aspx?familyid=c4e9b1dd-526d -407b-bc23-ebc2738b1b19

Microsoft ISA Server Radius OTP Authentication Bypass Vulnerability

References:

• ISA Server Homepage (Microsoft)
  
• Microsoft Homepage (Microsoft)
  
• MS09-031: ISA Server 2006 FBA and RADIUS OTP Bulletin (David B. Cross)
  
• MS09-031: More information about the ISA issue (Jonathan Ness)
  
• Microsoft Security Bulletin MS09-031 (Microsoft)