Microsoft Updates Windows, Browsers to Patch Critical Flaws

The 13 security bulletins released by Microsoft as part of the March 2016 Patch Tuesday address tens of vulnerabilities in Windows, Internet Explorer, Edge, Office, Server Software, and the .NET Framework.

One of the critical bulletins released this month, MS16-023, resolves 13 Internet Explorer vulnerabilities, the most severe of which can be exploited by a remote attacker to execute arbitrary code simply by getting the victim to visit a specially crafted website using Internet Explorer.

Another critical bulletin is MS16-024, which fixes 11 vulnerabilities in Microsoft Edge, including ones that also affect Internet Explorer.

MS16-026, which patches a couple of flaws in Windows, has also been rated critical. The issues, related to how the Windows Adobe Type Manager Library handles specially crafted OpenType fonts, can be exploited for denial-of-service (DoS) attacks and remote code execution.

“The OpenType Font parsing vulnerabilities noted in MS16-026 provide an example of how enhanced security measures within Windows 10 are making a difference. Although all of the affected operating systems are prone to denial of service or code execution as a result of CVE-2016-0120 and CVE-2016-0121 respectively, Microsoft notes that the impact is not actually the same for Windows 10 systems compared with the older OS versions,” Tripwire researcher Craig Young told SecurityWeek.

“In the case of the DoS attack, the Windows 10 architecture manages to limit the attack to a single affected application rather than the entire system. In the case of the code execution bug, an attacker might be able to take complete control over the system as opposed to under Windows 10 where code execution happens within an AppContainer sandbox process having limited privileges,” Young added.

The advisory for MS16-027 reveals that Windows is plagued by multiple critical remote code execution vulnerabilities that can be triggered when a user opens specially crafted media content hosted on a website.

MS16-028 fixes two issues related to the Microsoft Windows PDF Library. An attacker can exploit these security holes for remote code execution by getting the targeted user to open a specially crafted PDF file.

One interesting bulletin that has been rated “important” covers a Windows USB Mass Storage Class driver memory corruption bug that can be exploited for privilege escalation.

“What is interesting about this one is that the malicious USB device could be used to exploit even locked workstations where an attacker has temporary physical access,” Young explained. “In contrast, the LNK vulnerability exploited by Stuxnet and patched in MS10-046 would require that a victim browse to a malicious folder to trigger code execution. Another big difference is that since MS16-033 is a driver vulnerability, it gives the attacker a direct path to code execution within the kernel as opposed to in the context of a logged-in user.”

The advisories published by Microsoft for each of the 13 bulletins show that none of the vulnerabilities have been exploited in the wild, and exploits for them have not been made public.

Adobe also released security updates on Tuesday to address several vulnerabilities in Acrobat, Reader and Digital Editions.