From theregister.com
On Wednesday, shortly after security researcher Nguyen Jang posted a proof-of-concept exploit on GitHub that abuses a Microsoft Exchange vulnerability revealed earlier this month, GitHub, which is owned by Microsoft, removed code, to the alarm of security researchers.
The PoC code, something short of an actual functioning exploit, consisted of a 169-line Python file. It took advantage of CVE-2021-26855, a Microsoft Exchange Server flaw that allows an attacker to bypass authentication and act with administrative privileges.