Microsoft releases an emergency Windows 7 update

Microsoft has recently released a fix for a vulnerability in the .NET Framework. This is a rare and out-of-band update that comes weeks before the next regularly scheduled “Patch Tuesday” of mid-January.

This update however, is rather urgent, as it addresses a flaw that could allow attackers to exploit hash tables to perform a denial-of-service (DoS) attack against a website built with Microsoft’s ASP.NET application framework.

Usually, these attacks require thousands of malware-controlled systems in a botnet to overwhelm a site with requests, but this opening would allow an attacker to cripple a vulnerable site by sending a certain type of HTTP request, each consuming 100% of one CPU core, meaning the greater the requests, the higher the number of CPU power gained by the attacker.

“Attacks targeting this type of vulnerability are generically known as hash collision attacks,” said Microsoft.

The company also added that such a flaw is not specific to Microsoft’s Web services, but it also affects PHP 5, Java, .NET, v8 and even PHP 4, Ruby and Python. The people behind these platforms will release updates soon, but the holidays will dampen these efforts.

Source