CWE-358 Base Draft

Improperly Implemented Security Check for Standard

This vulnerability occurs when software fails to correctly implement one or more critical security checks required by a standard protocol, algorithm, or security technique.

Definition

What is CWE-358?

This vulnerability occurs when software fails to correctly implement one or more critical security checks required by a standard protocol, algorithm, or security technique.
Standards like TLS, OAuth, or cryptographic algorithms define specific security checks—such as certificate validation, timing attack mitigations, or proper error handling—to ensure their overall security. When developers implement these standards but miss, weaken, or incorrectly code these mandatory checks, they inadvertently introduce a security flaw while believing they are compliant. The software appears to follow the standard but contains a hidden weakness that attackers can exploit. This issue is particularly dangerous because it often evades casual review; the code looks correct on the surface. To prevent it, developers must treat the standard's security requirements as a strict checklist, not just a guideline. Security reviews and testing should specifically verify that each mandated check is implemented robustly and cannot be bypassed under any edge case or error condition.
Real-world impact

Real-world CVEs caused by CWE-358

  • CVE-2002-0862

    Browser does not verify Basic Constraints of a certificate, even though it is required, allowing spoofing of trusted certificates.

  • CVE-2002-0970

    Browser does not verify Basic Constraints of a certificate, even though it is required, allowing spoofing of trusted certificates.

  • CVE-2002-1407

    Browser does not verify Basic Constraints of a certificate, even though it is required, allowing spoofing of trusted certificates.

  • CVE-2005-0198

    Logic error prevents some required conditions from being enforced during Challenge-Response Authentication Mechanism with MD5 (CRAM-MD5).

  • CVE-2004-2163

    Shared secret not verified in a RADIUS response packet, allowing authentication bypass by spoofing server replies.

  • CVE-2005-2181

    Insufficient verification in VoIP implementation, in violation of standard, allows spoofed messages.

  • CVE-2005-2182

    Insufficient verification in VoIP implementation, in violation of standard, allows spoofed messages.

  • CVE-2005-2298

    Security check not applied to all components, allowing bypass.

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-358

  • Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
  • Implementation Validate input at trust boundaries; use allowlists, not denylists.
  • Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
  • Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
  • Operation Monitor logs for the runtime signals listed in the next section.
Detection signals

How to detect CWE-358

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

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Frequently asked questions

Frequently asked questions

What is CWE-358?

This vulnerability occurs when software fails to correctly implement one or more critical security checks required by a standard protocol, algorithm, or security technique.

How serious is CWE-358?

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-358?

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

How can I prevent CWE-358?

Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.

How does Plexicus detect and fix CWE-358?

Plexicus's SAST engine matches the data-flow signature for CWE-358 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-358?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/358.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-358

CWE-573 Parent

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CWE-304 Sibling

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CWE-325 Sibling

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Resources

Further reading

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