Enabling concurrent RDP increases your attack surface. If you forward port 3389 to the internet (never recommended), multiple active sessions give an attacker more persistence opportunities.
The patch modifies specific byte patterns inside termsrv.dll to bypass the session limit check. Common modifications include: Universal Termsrv.dll Patch For Windows 10
Regulated industries (healthcare, finance), enterprise production servers, or any environment where compliance is mandatory. Enabling concurrent RDP increases your attack surface
Tools look for specific patterns, such as 39 81 3C 06 00 00 , and replace them with code (e.g., B8 00 01 00 00 89 81 38 06 00 00 90 ) that forces the system to report that additional sessions are allowed. enterprise production servers