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CWE Reference

CWE-166: Improper Handling of Missing Special Element | Glexia

CWE-166 (Improper Handling of Missing Special Element) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE ATT&CK context.

Release 4.20weaknessDraft
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Glexia's Take · Automated analysis

CWE-166: Improper Handling of Missing Special Element

Improper Handling of Missing Special Element represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Executive Impact

  • Availability: DoS: Crash, Exit, or Restart

Developer Pattern

CWE-166 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.

Automation confidence

high confidence from CWE-166, 4.20.

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Official CWE Definition

CWE-166: Improper Handling of Missing Special Element

The product receives input from an upstream component, but it does not handle or incorrectly handles when an expected special element is missing.

Type
weakness
Abstraction
Base
Status
Draft
Source
MITRE CWE definition

Developer And Remediation Guidance

How teams prevent and detect this weakness

Causes

  • Missing validation
  • Unsafe defaults
  • Insufficient authorization or memory-safety invariant

Remediation

  • Developers should anticipate that special elements will be removed in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
  • Implementation:
  • Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

Detection

  • Code review
  • SAST
  • DAST
  • Focused regression tests

Mappings

Related CVEs, CWEs, and ATT&CK context

Related CWEs

Related CVEs

Related CVE mappings appear after CVE records are cross-indexed.

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ATT&CK Relevance

ATT&CK relevance is shown only when reviewed or responsibly inferred.