The US-CERT Current Activity web page is a regularly updated summary of the most frequent, high-impact types of security incidents currently being reported to the US-CERT.
Apple has released security update 2010-006 for Mac OS X and Mac OS X Server to address a vulnerability in the AFP package. This vulnerability may allow an attacker to bypass password validation and obtain sensitive information. The article indicates that this vulnerability does not affect systems prior to Mac OS X v10.6.
US-CERT encourages users and administrators to review Apple article HT4361 and apply any necessary updates to help mitigate the risks.
Microsoft has released a security advisory to alert users of a vulnerability affecting ASP.NET. Exploitation of this vulnerability may allow an attacker to obtain sensitive information or tamper with data.
US-CERT encourages administrators to review Microsoft security advisory 2416728 and apply any necessary workarounds until a fix is released by the vendor.
Update: Microsoft has indicated that this vulnerability affects all applications that rely on the ASP.NET platform. Microsoft has also updated the security advisory to include additional workaround details. The Microsoft SharePoint Team has updated its blog entry "Security Advisory 2416728 (Vulnerability in ASP.NET) and SharePoint" to assist users in how to mitigate these risks in SharePoint.
US-CERT will provide additional information as it becomes available.