This critical Windows security flaw could be as serious as WannaCry, experts claim

A vulnerability more serious than EternalBlue was sitting in Windows for some time, before being finally discovered and patched, experts have revealed. 

For those with shorter memory, EternalBlue was an NSA-built zero-day for Windows which gave birth to WannaCry, possibly the most devastating global ransomware threat to ever emerge.

Researchers from IBM, which discovered the flaw, said that it was even more potent as it resided in a wider range of network protocols, giving threat actors more flexibility when conducting their attacks.

Three-month headway

The flaw, tracked as CVE-2022-37958, isn’t exactly new, as it was discovered – and patched – three months ago. 

The news is that no one – not the researchers, not Microsoft issuing the patch – knew exactly how dangerous it really was. In reality, it allows threat actors to run malicious code without the need for authentication. Furthermore, it’s wormable, allowing threat actors to trigger a chain reaction of self-multiplying exploits on other vulnerable endpoints. In other words, the malware abusing the flaw could spread across devices like wildfire. 

Discussing the findings with Ars Technica, Valentina Palmiotti, the IBM security researcher who discovered the code-execution vulnerability, said an attacker could trigger the vulnerability via “any Windows application protocol that authenticates.”

“For example, the vulnerability can be triggered by trying to connect to an SMB share or via Remote Desktop. Some other examples include Internet exposed Microsoft IIS servers and SMTP servers that have Windows Authentication enabled. Of course, they can also be exploited on internal networks if left unpatched.”

When Microsoft first patched it three months ago, it believed the flaw could only allow threat actors to grab some sensitive information from the device, and as such, labeled it as “important”. Now, the company amended the rating, labeling it as “critical”, with a severity score of 8.1.

Unlike EternalBlue, which was a zero-day and left security experts and software makers scrambling to build a fix, the patch for this flaw has been available for three months now, so its effects should be somewhat limited. 

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Via: Ars Technica (opens in new tab)