OAuth Client ID Spoofing Lets Attackers Validate Stolen Microsoft Entra Credentials

Two separate threat actors have discovered a sneaky trick called OAuth client ID spoofing to dodge detection while exploiting Microsoft Entra ID environments. This method lets them check if stolen credentials work without triggering any alarms, making it harder for defenders to spot these attacks. The ability to validate credentials without a successful sign-in is a significant security risk, highlighting a major gap in Microsoft's cloud security measures. This development underscores the urgent need for enhanced monitoring and defenses against such sophisticated evasion tactics.