on Tuesday issued nine security bulletins that addressed 21 vulnerabilities. Redmond rated six of the flaws critical.
"Six of the patches this month are marked as critical, the most we've seen in a while," said Joshua Talbot, security intelligence manager at Symantec Security Response. "While all these vulnerabilities should be patched as soon as possible, we recommend paying particular attention to the HTML Layout vulnerability and the GDI Access Violation vulnerability, both of which allow for remote code execution."
Talbot noted that the GDI Access Violation vulnerability was made public in December. While exploit attempts so far have only resulted in Denial-of-Service attacks, he explained, there is a possibility that it can result in a full system takeover, which is of course the ultimate goal for attackers.
"Exploits for both of these vulnerabilities are likely to be hosted as drive-by downloads on maliciously created or otherwise compromised Web sites," Talbot said. "So, as always we strongly advise avoiding sites of unknown or questionable integrity to protect from attacks seeking to use these security holes."
Andrew Storms, director of security operations at nCircle, quipped that IT security teams are not getting any candy hearts from Microsoft for Patch Tuesday. Instead, every version of Internet Explorer gets an update. Typically, he said, people expect newer versions of IE to be a little safer but that's not the case this month.
"We are also getting another 'nasty gram' with MS12-013, a bug in the Microsoft C runtime library," Storms said. "At first glance, this bulletin looks like bad news, but so far the only attack vector is via Microsoft Media Player. Patch this one right after you patch Internet Explorer -- attackers will probably have exploits for this very shortly."
Tyler Reguly, technical manager of security and development at nCircle, said Microsoft knew exactly how to speak to his heart on Valentine's Day -- identifying some cross-site scripting issues related to SharePoint. He said that is definitely the best gift a Web-oriented security researcher could ask for.
"The most interesting bulletin today is the vulnerability affecting the C runtime library," Reguly said. "Everyone is likely to see this critical vulnerability and freak out. However, it's important to note that the attack vector is limited. It's not great news, but it does improve the situation."
Beyond Patch Tuesday
In other security news, Apple has released its patches in the shadow of Microsoft Patch Tuesday. This latest set of updates for Lion addresses 51 issues.
"It should be noted that some have reported application crashes after installing the 10.7 update," said Paul Henry, security and forensic analyst at Lumension. "It seems that Microsoft does not have any exclusivity when it comes to patches breaking things."
Henry also pointed to Mozilla's recent patch, which took care of a critical vulnerability that could be used to run attacker code and install software, without requiring any user interaction beyond normal browsing on Firefox.