Rule Category

OS-WINDOWS -- Snort has detected traffic targeting vulnerabilities in a Windows-based operating system. This does not include browser traffic or other software on the OS, but attacks against the OS itself. (such as?)

Alert Message

OS-WINDOWS Microsoft Windows Kerberos auth downgrade to DES MITM attempt

Rule Explanation

Kerberos in Microsoft Windows Server 2008 R2 and Windows 7 does not prevent a session from changing from strong encryption to DES encryption, which allows man-in-the-middle attackers to spoof network traffic and obtain sensitive information via a DES downgrade, aka "Kerberos Spoofing Vulnerability." Impact: CVSS base score 6.4 CVSS impact score 4.9 CVSS exploitability score 10.0 confidentialityImpact PARTIAL integrityImpact PARTIAL availabilityImpact PARTIAL 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-2011-0091
Kerberos in Microsoft Windows Server 2008 R2 and Windows 7 does not prevent a session from changing from strong encryption to DES encryption, which allows man-in-the-middle attackers to spoof network traffic and obtain sensitive information via a DES downgrade, aka "Kerberos Spoofing Vulnerability."
Details
SeverityMEDIUM Base Score6.4
Impact Score4.9 Exploit Score10.0
Confidentiality ImpactPARTIAL Integrity ImpactPARTIAL
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access