CWE-554 Variant Draft

ASP.NET Misconfiguration: Not Using Input Validation Framework

This vulnerability occurs when an ASP.NET application fails to implement a structured input validation framework, relying instead on ad-hoc or missing validation checks.

Definition

What is CWE-554?

This vulnerability occurs when an ASP.NET application fails to implement a structured input validation framework, relying instead on ad-hoc or missing validation checks.
ASP.NET provides built-in validation frameworks, like the Validator controls or model validation with Data Annotations, which automate the enforcement of security rules. When developers bypass these frameworks and write custom validation manually, they often introduce inconsistencies, miss critical checks, or fail to properly sanitize data across all entry points. This creates gaps where attackers can inject malicious input. Without a centralized validation strategy, the application becomes vulnerable to common attacks like SQL injection, cross-site scripting (XSS), and command injection. Using the framework ensures validation is applied consistently, reduces human error, and leverages security features that are maintained and updated by the platform. Adopting a structured approach is essential for building a robust security posture from the ground up.
Real-world impact

Real-world CVEs caused by CWE-554

No public CVE references are linked to this CWE in MITRE's catalog yet.

How attackers exploit it

Step-by-step attacker path

  1. 1

    Identify a code path that handles untrusted input without validation.

  2. 2

    Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.

  3. 3

    Deliver the payload through a normal request and observe the application's reaction.

  4. 4

    Iterate until the response leaks data, executes attacker code, or escalates privileges.

Vulnerable code example

Vulnerable pseudo

MITRE has not published a code example for this CWE. The pattern below is illustrative — see Resources for canonical references.

Vulnerable pseudo 
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Secure code example

Secure pseudo

Secure pseudo 
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist

How to prevent CWE-554

  • Architecture and Design Use the ASP.NET validation framework to check all program input before it is processed by the application. Example uses of the validation framework include checking to ensure that: - Phone number fields contain only valid characters in phone numbers - Boolean values are only "T" or "F" - Free-form strings are of a reasonable length and composition
Detection signals

How to detect CWE-554

SAST High

Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.

DAST Moderate

Run dynamic application security testing against the live endpoint.

Runtime Moderate

Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.

Code review Moderate

Code review: flag any new code that handles input from this surface without using the validated framework helpers.

Plexicus auto-fix

Plexicus auto-detects CWE-554 and opens a fix PR in under 60 seconds.

Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.

Get a demo Try Plexicus free
Frequently asked questions

Frequently asked questions

What is CWE-554?

This vulnerability occurs when an ASP.NET application fails to implement a structured input validation framework, relying instead on ad-hoc or missing validation checks.

How serious is CWE-554?

MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.

What languages or platforms are affected by CWE-554?

MITRE lists the following affected platforms: ASP.NET.

How can I prevent CWE-554?

Use the ASP.NET validation framework to check all program input before it is processed by the application. Example uses of the validation framework include checking to ensure that: - Phone number fields contain only valid characters in phone numbers - Boolean values are only "T" or "F" - Free-form strings are of a reasonable length and composition

How does Plexicus detect and fix CWE-554?

Plexicus's SAST engine matches the data-flow signature for CWE-554 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.

Where can I learn more about CWE-554?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/554.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-554

CWE-1173 Parent

Improper Use of Validation Framework

This vulnerability occurs when a software application either fails to use or incorrectly implements a built-in or library-provided input…

CWE-102 Sibling

Struts: Duplicate Validation Forms

This vulnerability occurs when an application defines multiple Struts validation forms with identical names. The framework then…

CWE-105 Sibling

Struts: Form Field Without Validator

This vulnerability occurs when a Struts application form contains an input field that lacks a corresponding validator, leaving it open to…

CWE-106 Sibling

Struts: Plug-in Framework not in Use

This weakness occurs when a Java application, particularly one using the Struts framework, does not implement a structured input…

CWE-108 Sibling

Struts: Unvalidated Action Form

In Apache Struts, every Action Form that processes user input must have a corresponding validation form configured. Missing this…

CWE-109 Sibling

Struts: Validator Turned Off

This vulnerability occurs when an application built with Apache Struts intentionally disables its built-in validation framework. By…

CWE-1174 Sibling

ASP.NET Misconfiguration: Improper Model Validation

This vulnerability occurs when an ASP.NET application either completely bypasses the built-in model validation system or implements it…

Resources

Further reading

Ready when you are

Don't Let Security
Weigh You Down.

Stop choosing between AI velocity and security debt. Plexicus is the only platform that runs Vibe Coding Security and ASPM in parallel — one workflow, every codebase.