Rule Category

SERVER-IIS -- Snort has detected traffic exploiting vulnerabilities in Microsoft IIS Web Servers.

Alert Message

SERVER-IIS Microsoft Windows IIS SChannel improper certificate verification

Rule Explanation

The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability." Impact: CVSS base score 7.1 CVSS impact score 6.9 CVSS exploitability score 8.6 confidentialityImpact NONE integrityImpact COMPLETE availabilityImpact COMPLETE Details: Ease of Attack:

What To Look For

Known Usage

No public information

False Positives

No known false positives

Contributors

Talos research team. This document was generated from data supplied by the national vulnerability database, a product of the national institute of standards and technology. For more information see [nvd].

MITRE ATT&CK Framework

Tactic:

Technique:

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

CVE

Additional Links

Rule Vulnerability

CVE Additional Information

CVE-2009-0085
The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability."
Details
SeverityHIGH Base Score7.1
Impact Score6.9 Exploit Score8.6
Confidentiality ImpactNONE Integrity ImpactCOMPLETE
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access