ZDI-07-055: Microsoft Windows DCERPC Authentication Denial of Service Vulnerability http://www.zerodayinitiative.com/advisories/ZDI-07-055.html October 10, 2007
-- CVE ID: CVE-2007-2228
-- Affected Vendor: Microsoft
-- Affected Products: Windows 2000 SP4 Windows XP SP2 Windows 2003 SP1 Windows Vista
-- TippingPoint(TM) IPS Customer Protection: TippingPoint IPS customers have been protected against this vulnerability since October 9, 2007 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 2007.10.09 - Digital Vaccine released to TippingPoint customers 2007.10.10 - Coordinated public release of advisory
-- Credit: This vulnerability was discovered by Tenable Network Security.
-- About the Zero Day Initiative (ZDI): Established by TippingPoint, a division of 3Com, The Zero Day Initiative (ZDI) represents a best-of-breed model for rewarding security researchers for responsibly disclosing discovered vulnerabilities.
Researchers interested in getting paid for their security research through the ZDI can find more information and sign-up at:
The ZDI is unique in how the acquired vulnerability information is used. 3Com does not re-sell the vulnerability details or any exploit code. Instead, upon notifying the affected product vendor, 3Com provides its customers with zero day protection through its intrusion prevention technology. Explicit details regarding the specifics of the vulnerability are not exposed to any parties until an official vendor patch is publicly available. Furthermore, with the altruistic aim of helping to secure a broader user base, 3Com provides this vulnerability information confidentially to security vendors (including competitors) who have a vulnerability protection or mitigation product.
CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is being sent by 3Com for the sole use of the intended recipient(s) and may contain confidential, proprietary and/or privileged information. Any unauthorized review, use, disclosure and/or distribution by any recipient is prohibited. If you are not the intended recipient, please delete and/or destroy all copies of this message regardless of form and any included attachments and notify 3Com immediately by contacting the sender via reply e-mail or forwarding to 3Com at email@example.com.