Report: PrintNightmare

Executive Summary On June 8, 2021, Microsoft released an advisory and patch for a critical vulnerability in the Windows Print Spooler. It was originally classified as a privilege escalation vulnerability. On June 27, 2021, researchers from QiAnXin claimed systems were still vulnerable after the patch and that the exploit could be used to gain remote code execution. A few days later researchers from Sangor released a proof-of-concept exploit on GitHub that validated the claim.