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๐Ÿšจ Unrestricted Resource Consumption โ€“ API4:2023 ๐Ÿš€

March 12, 2025

I'm kicking off a

series of articles on API Security

๐Ÿ” to help usโ€”

developers

๐Ÿ‘จ๐Ÿ’ป๐Ÿ‘ฉ๐Ÿ’ปโ€”better understand and implement

secure coding

in our software design. ๐Ÿ›ก๏ธ

Here is the fourth one: Unrestricted Resource Consumption

APIs are built to handle requests efficiently, but what happens when there are no limits? ๐Ÿคฏ Attackers can exploit APIs by overwhelming resources, leading to downtime, performance issues, and financial losses.


โš ๏ธ What is Unrestricted Resource Consumption?

This vulnerability occurs when an API fails to enforce limits on:

  • CPU usage ๐Ÿ–ฅ๏ธ โ€“ High-load requests slow down the system.
  • Memory consumption ๐Ÿง  โ€“ Large payloads crash the server.
  • Storage usage ๐Ÿ’พ โ€“ Unchecked uploads fill up disk space.
  • Network bandwidth ๐ŸŒ โ€“ Excessive requests cause DDoS-like effects.
  • Database queries ๐Ÿ“Š โ€“ Unoptimized queries degrade performance.


๐ŸŽฏ How Does It Happen?

๐Ÿšซ No rate limiting โ€“ Attackers flood the API with thousands of requests.

๐Ÿšซ Large file uploads โ€“ Unrestricted file sizes consume all available storage.

๐Ÿšซ Expensive operations โ€“ APIs allow computationally heavy queries.

๐Ÿšซ Unbounded loops โ€“ Recursive processing eats up CPU and memory.


๐Ÿ” Real-World Risks:

โœ… Denial of Service (DoS) โ€“ System becomes unresponsive ๐Ÿ“‰

โœ… Increased operational costs โ€“ Overuse of cloud resources ๐Ÿ’ธ

โœ… Data integrity issues โ€“ API overload leads to failed transactions โš ๏ธ


๐Ÿ›ก๏ธ How to Prevent It?

๐Ÿ”ธ Enforce rate limiting โณ โ€“ Limit requests per user/IP with throttling.

๐Ÿ”ธ Set quotas on resource usage ๐Ÿ“ โ€“ Restrict CPU, memory, and bandwidth.

๐Ÿ”ธ Limit payload sizes ๐Ÿ“ฆ โ€“ Reject oversized requests.

๐Ÿ”ธ Monitor API usage ๐Ÿ“Š โ€“ Detect abnormal activity early.

๐Ÿ”ธ Use async processing ๐Ÿ”„ โ€“ Prevent long-running requests from blocking resources.


๐Ÿš€ APIs should be scalable, but not limitless!

#APISecurity #OWASP #CyberSecurity #RateLimiting #SecureCoding