CWE-431: Missing Handler
Official CWE-431 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-431: Missing Handler
Missing Handler represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Other: Varies by Context
Developer Pattern
CWE-431 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.
Confidence
high confidence from CWE-431, 4.20.
Official CWE Definition
CWE-431: Missing Handler
A handler is not available or implemented.
When an exception is thrown and not caught, the process has given up an opportunity to decide if a given failure or event is worth a change in execution.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- If a Servlet does not catch all exceptions, it may reveal debugging information that will help an adversary form a plan of attack. In the following method a DNS lookup failure will cause the Servlet to throw an exception. When a Servlet throws an exception, the default error response the Servlet container sends back to the user typically includes debugging information. This information is of great value to an attacker.
Remediation
- Implementation: Handle all possible situations (e.g. error condition).
- Implementation: If an operation can throw an Exception, implement a handler for that specific exception.
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.