How to defend against Credential Stuffing attacks?

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Credential stuffing is a type of cyberattack where criminals test stolen username and password combinations on new websites to gain unauthorised access to user accounts. This attack relies on the common practice of password reuse across multiple websites.

Key Components of Credential Stuffing Defence

A successful attack relies on the ability to test millions of credentials in as short an amount of time as possible. The aim of the defender is to preferably block malicious attempts outright, and failing that, slow the attack down so much that it is no longer economical.

Effective credential stuffing mitigation involves a multi-layered approach:

1. Multi-factor authentication (MFA)
2. Advanced rate limiting
3. Bot detection and prevention
4. Real-time threat intelligence
5. Breached Password detection
6. User education and password policies

Multi-Factor Authentication (MFA)

MFA adds an extra layer of security by requiring users to provide additional verification beyond their password. This credential stuffing prevention technique makes it more difficult for attackers to access accounts, even if they have obtained valid login credentials. MFA alone is not enough, defenders must also implement the other steps or risk attackers obtaining lists of valid credentials and then moving onto social engineering to get the MFA code. Organisations also run the risk of large costs of SMS MFA requests being sent, or scammers calling their clients.

Advanced Rate Limiting

Rate limiting restricts the number of login attempts from a single IP address or device within a specified time frame. Advanced rate limiting techniques use machine learning algorithms to detect and block suspicious patterns of login attempts, enhancing credential stuffing mitigation.

Bot Detection and Prevention

Bot detection systems identify and block automated login attempts, which form the basis of most credential stuffing attacks. These systems analyse various factors such as login patterns, device fingerprints, and network behaviour to distinguish between human users and malicious bots.

Real-Time Threat Intelligence

Organisations can enhance their credential stuffing defence by incorporating real-time threat intelligence. This involves:

• Monitoring dark web forums for leaked credentials
• Sharing information about known attack patterns within the cybersecurity community
• Implementing dynamic blocklists of known malicious IP addresses

Breached Password Detection

By using the lists of breached credentials that attackers use, defenders can check whether a login request appears in a breached credential database. By monitoring requests you can get early warning of an attack by an increase of attempts using breached credentials. You can also alert/force password changes by affected users.

User Education and Password Policies

While technical measures form the backbone of credential stuffing prevention, user education plays a vital role. Organisations should:

• Encourage users to use unique, strong passwords for each account
• Promote the use of password managers
• Implement strict password policies that prevent the use of common or previously breached passwords

Credential stuffing mitigation requires a comprehensive approach that combines technical solutions with user awareness. By implementing these defence strategies, organisations can significantly reduce the risk of account takeovers and protect their users' sensitive information.