Cyber Posture

CWE · MITRE source

CWE-551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization

Abstraction: Base · CVEs in our corpus: 10

If a web server does not fully parse requested URLs before it examines them for authorization, it may be possible for an attacker to bypass authorization protection.

For instance, the character strings /./ and / both mean current directory. If /SomeDirectory is a protected directory and an attacker requests /./SomeDirectory, the attacker may be able to gain access to the resource if /./ is not converted to / before the authorization check is performed.

Last updated: 09 May 2026 03:25 UTC

NIST 800-53 r5 controls that address this weakness (0)AI

Control Title Family Why it addresses this CWE
No NIST controls proposed yet.

Top CVEs of this weakness type, ranked by Risk Priority

CVE Risk CVSS EPSS Published
CVE-2021-281646.75.30.93482021-04-01
CVE-2021-344296.75.30.93782021-07-15
CVE-2023-239245.110.00.51462023-02-01
CVE-2021-281652.27.50.11992021-04-01
CVE-2016-200302.09.80.00042026-03-16
CVE-2021-327771.78.60.00022021-08-24
CVE-2021-327791.78.60.00032021-08-24
CVE-2026-46361.68.10.00032026-04-02
CVE-2021-313841.57.20.00372021-10-19
CVE-2026-07071.15.30.00032026-01-08