Misconfigured Rate Limiting
TLDR: Misconfigured rate limiting, identified in the OWASP Top Ten under “Broken Access Control” and “Security Misconfiguration,” can lead to service abuse, denial-of-service attacks (DoS), and credential stuffing. Issues such as overly permissive thresholds, uneven enforcement across endpoints, and failure to log attempts leave applications vulnerable to automated attacks. Proper rate limiting ensures system stability and enhances security.
https://owasp.org/www-project-top-ten/
One common issue with rate limiting is setting overly high thresholds for allowable requests. For example, allowing 1,000 login attempts per minute enables attackers to perform brute force or credential stuffing attacks undetected. OWASP recommends defining strict and realistic thresholds based on the application's typical usage patterns.
https://owasp.org/www-project-api-security/
Another frequent vulnerability is uneven implementation of rate limiting across application endpoints. Attackers can target unprotected endpoints, such as APIs or secondary login mechanisms, to bypass controls. OWASP advises applying consistent rate limiting policies to all endpoints, including APIs, to mitigate abuse.
https://owasp.org/www-project-api-security/
Rate limiting mechanisms can also fail due to reliance on easily spoofed identifiers like IP addresses. Attackers can use proxies or botnets to bypass IP-based limits. OWASP suggests combining IP address tracking with session identifiers or user-specific metrics for more robust enforcement.
https://owasp.org/www-project-top-ten/
Improper handling of failed login attempts is another critical flaw. Without limiting repeated login failures, attackers can perform unlimited brute force attacks. OWASP recommends rate limiting login attempts and implementing progressive delays or temporary lockouts after repeated failures.
https://owasp.org/www-project-cheat-sheets/cheatsheets/Authentication_Cheat_Sheet.html
Neglecting to log and monitor rate-limiting events prevents detection of abuse patterns. Attackers can exploit this gap to fly under the radar. OWASP emphasizes integrating rate-limiting systems with SIEM tools to identify and analyze attack patterns.
https://owasp.org/www-project-cheat-sheets/cheatsheets/Logging_Cheat_Sheet.html
Rate limiting misconfigurations can inadvertently harm legitimate users. For instance, aggressive limits might block valid users during traffic spikes. OWASP suggests implementing adaptive rate limiting based on user behavior and application load to ensure a balance between security and usability.
https://owasp.org/www-project-top-ten/
Another issue arises from inadequate enforcement of rate limiting at the application layer. Attackers bypass these controls by directly targeting backend systems. OWASP advises enforcing rate limiting at both the application and infrastructure levels to ensure comprehensive protection.
https://owasp.org/www-project-top-ten/
Failing to communicate rate-limiting rules to users can create confusion and degrade user experience. Users unaware of limits might perceive errors as application failures. OWASP recommends providing clear error messages and documentation about rate-limiting policies to maintain transparency.
https://owasp.org/www-project-cheat-sheets/cheatsheets/Error_Handling_Cheat_Sheet.html
To mitigate these risks, developers should configure adaptive rate limiting, enforce consistent policies across endpoints, and monitor usage trends. Tools like OWASP ZAP and load testing frameworks can validate rate-limiting configurations during development. Regular audits and adherence to the OWASP Top Ten ensure robust and secure rate-limiting implementations.