CWE-168 – Improper Handling of Inconsistent Special Elements

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Description

The software does not properly handle input in which an inconsistency exists between two or more special characters or reserved words.

An example of this problem would be if paired characters appear in the wrong order, or if the special characters are not properly nested.

Modes of Introduction:

– Implementation

 

 

Related Weaknesses

CWE-159
CWE-703

 

Consequences

Availability, Access Control, Non-Repudiation: DoS: Crash, Exit, or Restart, Bypass Protection Mechanism, Hide Activities

 

Potential Mitigations

Phase:

Description: 

Developers should anticipate that inconsistent special elements will be injected/manipulated in the input vectors of their software system. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.

Phase: Implementation

Description: 

Phase: Implementation

Description: 

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.

CVE References