CWE-436: Interpretation Conflict
Official CWE-436 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-436: Interpretation Conflict
Interpretation Conflict represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Integrity,Other: Unexpected State,Varies by Context
Developer Pattern
CWE-436 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-436, 4.20.
Official CWE Definition
CWE-436: Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.
This is generally found in proxies, firewalls, anti-virus software, and other intermediary devices that monitor, allow, deny, or modify traffic based on how the client or server is expected to behave.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- The paper "Insertion, Evasion, and Denial of Service: Eluding Network Intrusion Detection" [REF-428] shows that OSes varied widely in how they manage unusual packets, which made it difficult or impossible for intrusion detection systems to properly detect certain attacker manipulations that took advantage of these OS differences.
- Null characters have different interpretations in Perl and C, which have security consequences when Perl invokes C functions. Similar problems have been reported in ASP [REF-429] and PHP.
Remediation
- Use safe APIs
- Centralize the control
- Add regression tests
- Review logs and telemetry for attempted abuse
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
- CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
- CWE-115: Misinterpretation of Input
- CWE-351: Insufficient Type Distinction
- CWE-434: Unrestricted Upload of File with Dangerous Type
- CWE-435: Improper Interaction Between Multiple Correctly-Behaving Entities
- CWE-437: Incomplete Model of Endpoint Features
- CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- CWE-626: Null Byte Interaction Error (Poison Null Byte)
- CWE-650: Trusting HTTP Permission Methods on the Server Side
- CWE-86: Improper Neutralization of Invalid Characters in Identifiers in Web Pages
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.