Fix it in your stack

Tested fixes for CWE-73 in Express, Flask, Spring Boot, ASP.NET Core, Next.js, FastAPI, Django, net/http, Rails and Laravel: the vulnerable code, the fix, a plausible fix that still fails, and the regression tests.

What MITRE says

The description above is MITRE’s definition of CWE-73 in CWE 4.20, a base-level weakness.

Common consequences MITRE lists

  • Integrity, Confidentiality: Read Files or Directories; Modify Files or Directories
  • Integrity, Confidentiality, Availability: Modify Files or Directories; Execute Unauthorized Code or Commands
  • Availability: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Other)

Guides on this site

Cites this weakness · Guide

Prevent file inclusion: LFI, RFI, dynamic imports and template names

Stop request data from choosing which file, module or template your application loads: local and remote file inclusion in PHP, dynamic require() and import() in Node.js, importlib and template names in Python, Thymeleaf view names in Spring, render in Rails, and the allowlist fix that works in all of them.

Practice

References

  1. CWE-73 in the MITRE CWE list (version 4.20)

This page is generated from MITRE’s CWE 4.20 catalogue (released 30 April 2026) and lists every guide, fix card and lab here that cites CWE-73.

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