CWE-447 Base Draft

Unimplemented or Unsupported Feature in UI

This vulnerability occurs when a user interface displays a security feature as active and functional, but the underlying code that powers it is either missing or disabled. Users receive visual…

Definition

What is CWE-447?

This vulnerability occurs when a user interface displays a security feature as active and functional, but the underlying code that powers it is either missing or disabled. Users receive visual confirmation that a protection is in place, creating a false sense of security.
This flaw is a classic case of UI deception, where the front-end presentation and the back-end logic are dangerously misaligned. It often happens during rushed development cycles, feature toggling, or when a security control is deprecated but its visual elements are not removed. Developers might see buttons, checkboxes, or status messages indicating features like 'encryption enabled,' 'admin audit logging active,' or '2FA required,' but these controls do nothing when interacted with, leaving the application exposed. The primary risk is that users and administrators will rely on these phantom protections, making riskier decisions under the assumption they are safe. To prevent this, development and QA teams must implement integration tests that verify the backend security logic is triggered for every front-end control. Code reviews should specifically check for 'dead' UI components and ensure any feature flag or configuration setting that disables a security function also consistently removes or grays out its interface elements.
Real-world impact

Real-world CVEs caused by CWE-447

  • CVE-2000-0127

    GUI configuration tool does not enable a security option when a checkbox is selected, although that option is honored when manually set in the configuration file.

  • CVE-2001-0863

    Router does not implement a specific keyword when it is used in an ACL, allowing filter bypass.

  • CVE-2001-0865

    Router does not implement a specific keyword when it is used in an ACL, allowing filter bypass.

  • CVE-2004-0979

    Web browser does not properly modify security setting when the user sets it.

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-447

  • Testing Perform functionality testing before deploying the application.
Detection signals

How to detect CWE-447

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-447 and opens a fix PR in under 60 seconds.

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Frequently asked questions

Frequently asked questions

What is CWE-447?

This vulnerability occurs when a user interface displays a security feature as active and functional, but the underlying code that powers it is either missing or disabled. Users receive visual confirmation that a protection is in place, creating a false sense of security.

How serious is CWE-447?

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-447?

MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.

How can I prevent CWE-447?

Perform functionality testing before deploying the application.

How does Plexicus detect and fix CWE-447?

Plexicus's SAST engine matches the data-flow signature for CWE-447 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-447?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/447.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-447

CWE-671 Parent

Lack of Administrator Control over Security

This weakness occurs when a system's built-in security settings cannot be adjusted by its administrator. This prevents tailoring security…

CWE-798 Sibling

Use of Hard-coded Credentials

This vulnerability occurs when software contains built-in, unchangeable authentication secrets like passwords or encryption keys within…

Resources

Further reading

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