CWE-180 — Incorrect Behavior Order: Validate Before Canonicalize
CWE-180: Incorrect Behavior Order: Validate Before Canonicalize
MITRE CWE weakness
| Kind | Weakness |
| Abstraction | Variant |
| Status | Draft |
| Likelihood of exploit | — |
Description
The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.
This can be used by an attacker to bypass the validation and launch attacks that expose weaknesses that would otherwise be prevented, such as injection.
Common consequences
- Access Control: Bypass Protection Mechanism
Mitigations
Implementation — 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.
References
- CWE page: https://cwe.mitre.org/data/definitions/180.html
- CWE list: https://cwe.mitre.org/data/index.html