https://blog.0patch.com/2021/12/free-micropatches-for.html
Wow, this is the third 0day found by the same researcher we’re patching in the last two weeks.
Abdelhamid Naceri, a talented security researcher, has been keeping us busy with 0days this year. In January we micropatched a local privilege escalation in Windows Installer they had found (already fixed by Microsoft), and in the last two weeks we fixed an incompletely patched local privilege escalation in User Profile Service and a local privilege escalation in Mobile Device Management Service (still 0days at the time of this writing).
Ten days ago, Abdelhamid tweeted a link to their GitHub repository containing a proof of concept for another unpatched vulnerability in Windows Installer. The vulnerability allows a local non-admin user to overwrite an existing file to which they do not have write access, and then arbitrarily change its content. This can easily be turned into local privilege escalation by overwriting a trusted system executable file with one’s own code – as demonstrated by Abdelhamid’s POC, which launches a command line window as Local System.
According to Cisco Talos, this vulnerability is being exploited in the wild. ..
Note that Abdelhamid’s POC also works on Windows 11 and likely Windows Server 2022, but we don’t support these Windows versions yet.
Micropatches for this vulnerability will be free until Microsoft has issued an official fix
