TippingPoint Zero Day Initiative
 

Microsoft Windows DCERPC Authentication Denial of Service Vulnerability

ZDI-07-055: October 10th, 2007

CVE ID

Affected Vendors

Affected Products

    Windows 2000 SP4
    Windows XP SP2
    Windows 2003 SP1
    Windows Vista

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 5657. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to crash systems with vulnerable installations of the Microsoft Windows operating system. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the RPC runtime library rpcrt4.dll during the parsing of RPC-level authentication messages. When parsing packets with the authentication type of NTLMSSP and the authentication level of PACKET, an invalid memory dereference can occur if the verification trailer signature is initialized to 0 as opposed to the standard NTLM signature. Successful exploitation crashes the RPC service and subsequently the entire operating system.

Vendor Response

Microsoft has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline

    2007-02-05 - Vulnerability reported to vendor
    2007-10-10 - Coordinated public release of advisory

Credit

This vulnerability was discovered by:
    Tenable Network Security