Fix it in your stack

Tested fixes for CWE-113 in Express, Flask and Spring Boot: 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-113 in CWE 4.20, a variant-level weakness.

Common consequences MITRE lists

  • Integrity, Access Control: Modify Application Data; Gain Privileges or Assume Identity

Guides on this site

Cites this weakness · Guide

Prevent CRLF header injection, log forging and CSV formula injection

Carriage return and line feed separate HTTP header fields, log records and CSV rows, and a leading = turns a spreadsheet cell into a formula. Let the framework write headers, log structured JSON, and neutralize formula triggers in exports.

References

  1. CWE-113 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-113.

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