Security News > 2021 > July > Enterprises Warned of New PetitPotam Attack Exposing Windows Domains
Enterprises have been warned of a new attack method that can be used by malicious actors to take complete control of a Windows domain.
An unauthenticated attacker can use PetitPotam to get a targeted server to connect to their server and perform NTLM authentication.
The SANS Institute's Internet Storm Center has published a step-by-step description of the attack.
After the PoC was released, Microsoft published an advisory saying that PetitPotam "Is a classic NTLM Relay Attack," noting that the company previously provided numerous mitigation options for such attacks.
"To prevent NTLM Relay Attacks on networks with NTLM enabled, domain administrators must ensure that services that permit NTLM authentication make use of protections such as Extended Protection for Authentication or signing features such as SMB signing," Microsoft said.
SANS's Bojan Zdrnjan noted, "What missed is the fact that the PetitPotam vulnerability ... is a completely separate issue - it allows an attacker to provoke a server to authenticate to an arbitrary machine. Abusing AD CS is just one way to use this - any service that allows NTLM authentication can probably be abused similarly."