The bug (CVE-2021-1675) exists in the Windows Print Spooler and has been dubbed “PrintNightmare” by researchers. It was originally addressed in June’s Patch Tuesday updates from Microsoft as a minor elevation-of-privilege vulnerability, but the listing was updated last week after researchers from Tencent and NSFOCUS TIANJI Lab figured out it could be used for RCE. The patch, according to many, appears to fail against the RCE aspect of the bug.

I have created a PoC for the vulnerability.