Improper Restriction of Authentication Attempts in cURL

How it was found

Summary:

The authentication mechanism in cURL does not properly restrict the number of failed authentication attempts, allowing an attacker to brute-force credentials. This issue affects authentication-based requests and could lead to unauthorized access if an attacker successfully guesses a valid password.

Affected Version:

cURL version: [Specify version] Platform: [Specify OS and environment] (curl -V output: [Attach output])

Steps To Reproduce:

Use a valid username but an incorrect password to make an authentication request via cURL:

curl -u valid_user:wrong_password http://target-url.com

Observe that there is no lockout or delay after multiple failed attempts.

Automate the process using a brute-force script:

for i in {1..1000}; do curl -u valid_user:password$i http://target-url.com; done

If a correct password is found, the attacker gains unauthorized access.

Supporting Material/References:

[Attach logs or screenshots showing multiple failed attempts without any lockout]

[Any relevant documentation that supports this claim]

Impact:

Allows brute-force attacks against user accounts.

Potential unauthorized access leading to data breaches.

Can be exploited remotely if authentication is exposed.

Recommended Fix:

Implement rate-limiting after multiple failed authentication attempts.

Introduce CAPTCHA or multi-factor authentication (MFA).

Enforce temporary account lockouts after a predefined number of failures.

Severity: Critical 🚨

This vulnerability can be exploited remotely, leading to unauthorized access, making it a high-impact security risk

Impact

Allows brute-force attacks against user accounts.

Potential unauthorized access leading to data breaches.

Can be exploited remotely if authentication is exposed.