n February 2023, Kaspersky technologies detected a number of attempts to execute similar elevation-of-privilege exploits on Microsoft Windows servers belonging to small and medium-sized businesses in the Middle East, in North America, and previously in Asia regions. These exploits were very similar to already known Common Log File System (CLFS) driver exploits that we analyzed previously, but we decided to double check and it was worth it – one of the exploits turned out to be a zero-day, supporting different versions and builds of Windows, including Windows 11. The exploit was highly obfuscated with more than 80% of the its code being “junk” elegantly compiled into the binary, but we quickly fully reverse-engineered it and reported our findings to Microsoft. Microsoft assigned CVE-2023-28252 to the Common Log File System elevation-of-privilege vulnerability, and a patch was released on April 11, 2023, as part of April Patch Tuesday.

Microsoft addresses 97 CVEs, including one that was exploited in the wild as a zero day

Apple has released emergency security updates to address two new zero-day vulnerabilities exploited in attacks to compromise iPhones, Macs, and iPads.

* Mandiant tracked 55 zero-day vulnerabilities that we judge were exploited in 2022. Although this count is lower than the record-breaking 81 zero-days exploited in 2021, it still represents almost triple the number from 2020. * Chinese state-sponsored cyber espionage groups exploited more zero-days than other cyber espionage actors in 2022, which is consistent with previous years. * We identified four zero-day vulnerabilities exploited by financially motivated threat actors. 75% of these instances appear to be linked to ransomware operations. * Products from Microsoft, Google, and Apple made up the majority of zero-day vulnerabilities in 2022, consistent with previous years. The most exploited product types were operating systems (OS) (19), followed by browsers (11), security, IT, and network management products (10), and mobile OS (6).