What is the best way to mitigate password replay attacks in a multi-tenant SaaS application?

In the context of mitigating password replay attacks, requiring and implementing two-factor authentication (2FA) is a highly effective strategy. Password replay attacks occur when an attacker captures a password and then uses it to gain unauthorized access to a user's account. While a strong password policy can help, it is not sufficient on its own, as passwords can still be intercepted during transmission or through compromised systems.

Two-factor authentication adds an additional layer of security by requiring not only a password but also a second factor, which could be something that the user possesses (like a mobile device for receiving an OTP) or something inherent to the user (like a fingerprint). This means that even if an attacker captures the password, they would still need the second factor to gain access, significantly reducing the risk of unauthorized access due to a compromised password.

Other options, while relevant to security in general, do not specifically address the risk of replay attacks as effectively. For example, implementing destination resources authentication primarily focuses on the verification of the target resources, which does not prevent replay attacks directly. Similarly, removing administrator privileges from users' laptops and combining network authentication with physical security may enhance overall security, but they are not direct mitigations against the specific threat posed by password replay attacks.