CVE-2021-43795: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Armeria is an open source microservice framework. In affected versions an attacker can access an Armeria server’s local file system beyond its restricted directory by sending an HTTP request whose path contains %2F (encoded /), such as /files/..%2Fsecrets.txt, bypassing Armeria’s path validation logic. Armeria 1.13.4 or above contains the hardened path validation logic that handles %2F properly. This vulnerability can be worked around by inserting a decorator that performs an additional validation on the request path.