CWE-529 is a product that stores access control list files in a directory or container reachable by actors outside the intended control sphere.
How it happens
An ACL file records who may do what. If it sits in a web root, a shared folder or a public archive, anyone can read it. Typical causes are a deployment that copies the whole config directory, a backup left in a served path, or file permissions set too wide.
What an attacker gains
MITRE says exposure may give the attacker information about the configuration of the site or system. That can then be used to bypass the intended security policy or to identify trusted systems from which an attack can be launched. The listed impacts are on confidentiality and access control.
How to find it
The record lists no detection methods. Request likely ACL file paths on your own servers from outside, and check archives and build artifacts for configuration files before release.
How to fix it
MITRE's mitigation is to protect access control list files: keep them outside any served directory and restrict read permission to the account that needs them.
Quick check
What does an exposed ACL file tell an attacker?
How the system is configured, and which systems are trusted.
