June is a big month for Microsoft patches, there are 10 bulletins covering 34 vulnerabilities. Four bulletins address 0-day issues, the most significant being MS10-035, which fixes the 0-day published by Core Security for an information disclosure vulnerability originally published in February 2010. It also fixes the PWN2OWN vulnerability that security researcher Peter Vreugdenhil used to win ZDI’S competition at CANSECWEST, not a 0-day but high profile as it bypassed all built-in protections such as DEP and ASLR by combining multiple attack methods. MS10-039 addresses a second 0-day, the vulnerability in SharePoint, described by Microsoft in KB983438. MS10-032 and MS10-041 are the additional updates that fix vulnerabilities that were previously disclosed.
The most critical bulletins this month are MS10-035 for Internet Explorer, MS10-033 for DirectShow, and MS10-038 for Excel in Microsoft Office. All versions of IE, including IE8 are affected by MS10-035. There are 6 vulnerabilities in the update, 2 critical and it has an overall exploitability index of 1, indicating that an exploit is expected within 30 days. MS10-033 is a vulnerability in the MJPEG codec and affects a large number of Microsoft products, but its main attack vector is going to be through media files delivered through the Internet to Windows Media Player or IE. Excel has 14 vulnerabilities covered by MS10-038, with 11 in Office XP and only 3 in more recent versions (2003,2007). These vulnerabilities can be used to trigger code execution when a malicious file is opened by the user. The new Office 2010, which is scheduled to be released later this month, is not affected by any of the vulnerabilities.
MS10-032 addresses a local escalation of privilege vulnerability. While it is not remotely exploitable through any Microsoft product, 3rd party applications could expose it and provide a remote attack possibility.
MS10-040 is a remotely exploitable vulnerability in all versions of IIS, but it is present only if the administrator has downloaded and installed the Channel Binding Update and enabled Windows Authentication. It further requires an account on the system, reducing the number of vulnerable hosts to a small subset.
In related news, Adobe which published an advisory for a critical 0-day vulnerability in Flash and Reader on Friday, announced that they will provide patches on June 10th and June 29th, respectively, 2 dates that IT administrators should track closely as exploits for the vulnerability are widely available.