A rate limit defines the maximum number of requests a user or system can make to a service or endpoint within a specified timeframe. Rate limiting helps prevent misuse or overuse of resources, such as API requests, database queries or server processes.
A rate limit is a mechanism to limit the number of requests a user can make to a server in a given time period. When this limitation is either not set or misconfigured, attackers can exploit the system, potentially leading to a Denial of Service (DoS) attack.
When rate limits are either missing or misconfigured, attackers can exploit the system by flooding it with excessive requests. Here are some ways this vulnerability can be exploited:
First, identify the endpoints and resources in your application that are most likely to be targeted by abuse. This includes:
Once you've identified the critical endpoints, you can implement a rate limiting mechanism. There are various approaches to achieve this:
Once the rate limiting mechanism is in place, it’s crucial to set the right thresholds. These limits should be based on the expected usage patterns of legitimate users.
For example:For critical endpoints such as login and password recovery, consider integrating CAPTCHA or Multi-Factor Authentication (MFA) alongside rate limiting. These mechanisms help thwart automated attacks, especially brute force attempts, by introducing additional layers of verification.
Once rate limiting is in place, you should actively monitor the system for signs of abuse. Set up alerting mechanisms to notify administrators of unusual request patterns or when rate limits are being hit frequently.
For systems that are distributed across multiple servers or microservices, ensure that rate limiting is applied consistently across all components. You can use tools like Redis or specialized load balancers to synchronize rate limits across servers.