Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Vulnerabilities

Microsoft to Issue Emergency Fix to Address Hash Collision Attack Vulnerability on Thursday

In a rare move, Microsoft is breaking its normal procedures and will issue an emergency out-of-band security update on Thursday to address a recently disclosed vulnerability that affects various Web platforms industry-wide.

In a rare move, Microsoft is breaking its normal procedures and will issue an emergency out-of-band security update on Thursday to address a recently disclosed vulnerability that affects various Web platforms industry-wide.

Update: Microsoft has released the security bulletin as planned. The patches are available here.

Microsoft Security Bulletin The vulnerability comes in the way attackers could exploit hash tables to cause a denial of service (DoS) condition. “Attacks targeting this type of vulnerability are generically known as hash collision attacks,” Microsoft notes. “Attacks such as these are not specific to Microsoft technologies and affect other web service software providers.”

According to n.runs AG, the research firm who discovered the issue, the vulnerability has been discovered to impact PHP 5, Java, .NET, and Google’s v8, while PHP 4, Ruby, and Python are somewhat vulnerable. The Ruby security team has addressed the issue, as well as Tomcat.

According to Microsoft, the vulnerability affects all versions of Microsoft .NET Framework and could allow for an unauthenticated denial of service attack on servers that serve ASP.NET pages. Sites that only serve static content or disallow dynamic content types listed in the mitigation factors below are not vulnerable.

Microsoft released the bulletin on December 29, 2011, at 10:00 AM Pacific Time, and said it addresses vulnerabilities in all supported releases of Microsoft Windows.

“Hash tables are a commonly used data structure in most programming languages. Web application servers or platforms commonly parse attacker-controlled POST form data into hash tables automatically, so that they can be accessed by application developers,” n.runs AG’s report explains.

“The impact of this vulnerability is similar to other Denial of Service attacks that have been released in the past, such as the Slowloris DoS or the HTTP POST DoS,” Chris Eng, Vice President of Research at Veracode told SecurityWeek. “Unlike traditional DoS attacks, they could be conducted with very small amounts of bandwidth. This hash table multi-collision bug shares that property. What’s particularly unique about this bug is that it affects a broader range of platforms and technologies in a virtually identical way.”

Microsoft is hosting a webcast which will provide additional information and address questions on the out-of-band security bulletin on December 29, 2011, at 1:00 PM Pacific Time. You can register for the webcast here.

Advertisement. Scroll to continue reading.

The research from n.runs AG explaining the vulnerability in detail is available here. Information on mitigation and patches are available for the following: PHP | Ruby | Microsoft | Tomcat

Written By

For more than 15 years, Mike Lennon has been closely monitoring the threat landscape and analyzing trends in the National Security and enterprise cybersecurity space. In his role at SecurityWeek, he oversees the editorial direction of the publication and is the Director of several leading security industry conferences around the world.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...

Vulnerabilities

A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

Cybercrime

Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.

Vulnerabilities

Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.

Vulnerabilities

The latest Chrome update brings patches for eight vulnerabilities, including seven reported by external researchers.