CWE-180: Incorrect Behavior Order: Validate Before Canonicalize
The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.
How it's found
Incorrect Behavior Order: Validate Before Canonicalize is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
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.
Vulnerable vs. safe
File f = new File(path);return f.getCanonicalPath();String path = getInputPath();if (path.startsWith("/safe_dir/")){}return f.getCanonicalPath();String path = getInputPath();File f = new File(path);if (f.getCanonicalPath().startsWith("/safe_dir/")){}Consequences
- 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.
Where this fits in a TurboPentest engagement
TurboPentest's agentic pentest is powerful and covers a broad range of issues automatically. This particular class is best confirmed in a manual IntegSec engagement, where human pentesters apply deeper methodology and a larger context window than any automated pass.
Frequently asked questions
What is CWE-180?
The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.
How do you find Incorrect Behavior Order: Validate Before Canonicalize?
Incorrect Behavior Order: Validate Before Canonicalize is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
What is the impact of CWE-180?
Bypass Protection Mechanism
Does TurboPentest test for Incorrect Behavior Order: Validate Before Canonicalize?
TurboPentest's agentic pentest is powerful and covers a broad range of issues automatically. This particular class is best confirmed in a manual IntegSec engagement, where human pentesters apply deeper methodology and a larger context window than any automated pass.
Related CWEs
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