Rule Category

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

Alert Message

SERVER-IIS Microsoft Windows IIS .NET null character username truncation attempt

Rule Explanation

The Forms Authentication feature in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 allows remote authenticated users to obtain access to arbitrary user accounts via a crafted username, aka "ASP.Net Forms Authentication Bypass Vulnerability." Impact: CVSS base score 8.5 CVSS impact score 10.0 CVSS exploitability score 6.8 confidentialityImpact COMPLETE 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-2011-3416
The Forms Authentication feature in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 allows remote authenticated users to obtain access to arbitrary user accounts via a crafted username, aka "ASP.Net Forms Authentication Bypass Vulnerability."
Details
SeverityHIGH Base Score8.5
Impact Score10.0 Exploit Score6.8
Confidentiality ImpactCOMPLETE Integrity ImpactCOMPLETE
Availability ImpactCOMPLETE Access Vector
AuthenticationSINGLE Ease of Access