CWE•Class•Draft•2 recent CVEs
CWE-159Improper Handling of Invalid Use of Special Elements
Description
The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity.
Common consequences
- Integrity→Unexpected State
Potential mitigations
- Developers should anticipate that special elements will be injected/removed/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.
- Implementation[object Object]
- ImplementationWhile it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or whit
- ImplementationInputs 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.