This vulnerability occurs when software incorrectly interprets or processes input data, leading to unintended and potentially harmful security consequences. The flawed interpretation can come from user-provided data, external systems, or other components.
At its core, this weakness is about a mismatch between what the software expects and how it actually handles incoming information. Instead of rejecting malformed data or processing it safely, the system assigns it the wrong meaning or context. This misinterpretation then ripples through the application logic, creating openings for attackers to manipulate behavior, bypass checks, or corrupt data. Common triggers include incorrect character encoding handling, flawed protocol parsing, or mistaken assumptions about data structure or boundaries. For developers, prevention starts with adopting a strict and consistent parsing strategy. Always validate and sanitize all input against a well-defined schema before processing. Use established libraries for complex formats (like XML, JSON, or network protocols) rather than custom parsers. Implement clear data transformation pipelines and log parsing decisions to catch discrepancies early. Assume input is malicious until proven otherwise, and design your data handling to fail securely—defaulting to a denied state when interpretation fails.
Impact: Unexpected State