The CaseInsensitiveHashProvider.getHashCode function in the HashTable implementation in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters, aka "Collisions in HashTable May Cause DoS Vulnerability."

The remote Windows host is running a version of ASP.NET that is affected by a hash collision denial of service. A flaw exists in the way ASP.NET generates hash tables for user-supplied values.
By sending a small number of specially crafted POST requests to a web server that uses ASP.NET, an attacker can take advantage of this flaw to cause a denial of service condition.

Note that this script only runs if 'Report paranoia' is set to 'Paranoid' and the 'Perofrm thorough tests' setting is enabled.

The remote Windows host is running a version of the Microsoft ASP.NET Framework that has multiple vulnerabilities.  These include:

  - A flaw exists in the way ASP.NET generates hash tables     for user-supplied values.  By sending a small number of     specially crafted posts to an ASP.NET server, an     attacker can take advantage of this flaw to cause a     denial of service condition.  (CVE-2011-3414)

  - The Framework does not properly validate return URLs     during the forms authentication process, which could     allow an attacker to redirect a victim to a malicious     website. (CVE-2011-3415)

  - ASP.NET forms authentication contains a vulnerability     that could allow an attacker that already has a     registered user on an application to gain the     privileges of another known user. (CVE-2011-3416)

  - An elevation of privilege vulnerability exists in the     way that ASP.NET Framework handles cached content when     Forms Authentication is used with sliding expiry.  An     attacker can take advantage of this vulnerability to     execute code in the context of a target user by     tricking the user into visiting a specially crafted     link. (CVE-2011-3417)

ID	Name	Product	Family	Severity
57561	MS11-100: ASP.NET Could Allow Denial of Service (2638420) (uncredentialed check)	Nessus	CGI abuses	medium
57414	MS11-100: Vulnerabilities in .NET Framework Could Allow Elevation of Privilege (2638420)	Nessus	Windows : Microsoft Bulletins	high

Detections

Analytics

CVE-2011-3414

high

Tenable Plugins

medium

high