CWE-179 — Incorrect Behavior Order: Early Validation
CWE-179: Incorrect Behavior Order: Early Validation
MITRE CWE weakness
| Kind | Weakness |
| Abstraction | Base |
| Status | Incomplete |
| Likelihood of exploit | — |
Description
The product validates input before applying protection mechanisms that modify the input, which could allow an attacker to bypass the validation via dangerous inputs that only arise after the modification.
Product needs to validate data at the proper time, after data has been canonicalized and cleansed. Early validation is susceptible to various manipulations that result in dangerous inputs that are produced by canonicalization and cleansing.
Common consequences
- Access Control, Integrity: Bypass Protection Mechanism, Execute Unauthorized Code or Commands
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/179.html
- CWE list: https://cwe.mitre.org/data/index.html