What is Credential Stuffing? (How it Works, How to Prevent)

What is Credential Stuffing?

Credential stuffing is a term for hacking in which a hacker secures user credentials by breaching a system and then tries to utilize those credentials with other systems. Like different types of related hacking, Credential stuffing attacks rely on hackers to break into a network and steal sensitive user information such as passwords and usernames.

Credential stuffing occurs when hackers take stolen information from one site or system and use it in a brute force hacking attempt to gain access to multiple other systems. Hackers will sometimes check whether a password or username can be used on another website or whether it is related to the original.

Hackers may, for example, get access to a list of usernames and passwords for a specific merchant and attempt to use those usernames and passwords on a banking website. The assumption is that by trying many of these assaults, hackers will be able to determine whether any users have reused passwords or user permissions, allowing hackers to access various systems using stolen login data. Credential stuffing can lead to identity theft in some cases.

How Does Credential Stuffing Work?

Extensive lists of username/password pairings that have been disclosed are used in credential stuffing attacks. In some data breaches, incorrect credential storage leads to the exposure of the whole password database. In other cases, thieves utilize password guessing attempts to breach some users' credentials. Credential stuffers can also use phishing and other similar assaults to access usernames and passwords.

These lists of users and passwords are given to a botnet, which tries to log into specific target sites with them. For example, the credentials stolen from a travel website may be checked against a vast banking institution. If any users used the same credentials on both sites, the attackers might be able to get into their accounts successfully.

Fraudsters may utilize good username/password pairs for various purposes depending on the account in question after detecting them. Some credentials allow attackers to get access to corporate networks and systems, while others allow them to make use of the account owner's bank account. This access could be used by a credential stuffing organization or sold to another party.

What Makes Credential Stuffing So Effective?

Credential stuffing assaults have a relatively low success rate, according to statistics. According to many estimates, this rate is around 0.1 percent, which means that for every thousand accounts an attacker tries to hack, they will only succeed once. Despite the low success rate, the sheer volume of credential collections traded by attackers makes credential stuffing worthwhile.

These databases include millions, if not billions, of login credentials. If an attacker possesses one million sets of credentials, they may be able to breach around 1,000 accounts.

The assault is worthwhile if even a tiny percentage of the broken accounts deliver valuable data (typically in credit card information or sensitive data that can be exploited in phishing attacks). Furthermore, the attacker can repeat the operation on several services using the same sets of credentials. Credential stuffing has also become a potential assault because of advancements in bot technology.

Deliberate time delays and blocking users' IP addresses who make many failed login attempts are common security mechanisms integrated into web application login forms. Modern credential stuffing software works around these safeguards by simultaneously deploying bots to attempt multiple logins from various device types and IP addresses.

The malicious bot's purpose is to blend the attacker's login attempts with regular login activity, which succeeds admirably. The increase in the overall volume of login attempts is frequently the only indicator that the targeted firm is being attacked. Even then, the targeted organization will have difficulty thwarting these attempts without jeopardizing legitimate users' ability to access the service.

Credential stuffing attacks are successful primarily because people reuse passwords. According to studies, most users reuse their login credentials for several services, with some estimations as high as 85 percent. Credential stuffing will continue to be profitable as long as this practice is practiced.

Brute Force Attacks vs. Credential Stuffing Attacks

Credential stuffing is a sort of cyberattack that uses brute force. However, the two are significantly different in practice, as are the best approaches to protect your systems against them. By altering the characters and numbers of passwords, brute force attacks attempt to guess them.

You can use brute force protection, a CAPTCHA, or ask your users to use a stronger password to protect themselves from failed login attempts. However, because the password is already known, a strong password will not prevent a cybercriminal from accessing an account via credential stuffing.

Even CAPTCHA or brute force defense is limited in its ability to protect users because users change their passwords in predictable patterns, and attackers have a compromised password to iterate from.

How Can Credential Stuffing Be Prevented?

Both personal and corporate security is jeopardized by credential stuffing. When a credential stuffing assault succeeds, the attacker has access to the user's account, which may contain sensitive information or the ability to conduct financial transactions or perform other privileged actions on the user's behalf. Despite the well-publicized dangers of password reuse, most users do not change their password habits.

If passwords are overused across personal and commercial accounts, credential stuffing can endanger the corporation. To reduce the danger of credential stuffing attacks, businesses can take the following steps −

  • Multi-Factor Authentication (MFA) − Credential stuffing attacks rely on the attacker's ability to log into an account with simply a username and password. MFA or 2FA makes these assaults more challenging because the attacker requires a one-time code to log in successfully

  • CAPTCHA − The majority of credential stuffing assaults are automated. CAPTCHA on login pages can prevent some automated traffic from accessing the site and testing possible passwords.

  • Anti-Bot Solutions − Organizations can use anti-bot solutions in addition to CAPTCHA to prevent credential stuffing traffic. These tools employ behavioral anomalies to distinguish between human and automated site users and restrict suspect traffic.

  • Monitoring Website Traffic − A credential stuffing attack entails many failed login attempts. An organization's ability to stop or limit these assaults may be determined by monitoring traffic to login pages.

  • Credential Stuffing Bots Using Lists of Breached Credentials −Credential stuffing bots usually use lists of credentials disclosed in data breaches. User passwords can be checked against lists of weak passwords or services like "HaveIBeenPwned" to see if they're vulnerable to credential stuffing.