Patch now! Microsoft issues critical security updates as PCs attacked through zero-day flaw

Windows users are once again being told to update their systems with the latest security patches from Microsoft, following the discovery of critical vulnerabilities – including ones that are already being exploited in the wild or could be used to fuel a fast-spreading worm.

In its latest “Patch Tuesday” update, Microsoft released patches that addressed over 60 security holes in its products, including five vulnerabilities ranked as “critical.”

The most urgent of the vulnerabilities to patch is arguably a privilege escalation flaw in the Windows Common Log File System (CLFS), for which exploit code has been made publicly available.

The zero-day flaw, tracked as CVE-2022-37969, was disclosed to Microsoft by researchers from four security vendors. This suggests that its use has not been limited to one targeted organization but may be widely exploited.

Microsoft warns that a malicious attacker who successfully exploited the CVE-2022-37969 vulnerability could gain powerful system privileges, but that they would already need to have access and the ability to run code on the targeted PC.

Things clearly would be worse if the vulnerability allowed for remote code execution by hackers who didn’t already have a foothold within a targeted system. However, the fact that exploit code has been made available and there are reports of exploitation means that it should still be treated seriously.

Also serious is CVE-2022-34718, a remote code execution flaw in the Windows TCP/IP service that could be exploited by a worm that could spread without user interaction.

According to Microsoft, an attacker could send a specially crafted IPv6 packet to a Windows node where IPSec is enabled and allow remote malicious code to run and exploit the PC.

Although Microsoft has seen no evidence that the CVE-2022-34718 flaw has been publicly disclosed or exploited, it has flagged the security vulnerability as “exploitation more likely.”

Frustratingly, Microsoft does not offer much in publicly detailing why it has labeled this and other flaws it has patched in its latest security update as “exploitation more likely.” ┬áThis lack of transparency does make it more difficult for companies to determine which vulnerabilities should be patched as a matter of priority or what mitigations they should put in place, particularly when they may be concerned about disrupting their other business activities.

It’s not as though IT departments in companies aren’t already busy dealing with a wave of security patches from other vendors, including Apple and Adobe.