Sławek Naczyński

**Name of the Vulnerable Software and Affected Versions** SimpleSAMLphp versions prior to 1.18.6 **Description** The module controller in `SimpleSAMLModule` has code to identify paths ending with `.php` and process those as PHP code. However, the check does not account for uppercase letters. If someone requests a path ending with e.g. `.PHP` and the server is serving the code from a case-insensitive file system, such as on Windows, the processing of the PHP code does not occur, and the source code is instead presented to the browser. An attacker may use this issue to gain access to the source code in third-party modules that is meant to be private, or even sensitive. The attack surface is considered small, as the attack will only work when SimpleSAMLphp serves such content from a file system that is not case-sensitive, such as on Windows. **Recommendations** Upgrade the SimpleSAMLphp installation to version 1.18.6. As a temporary workaround, consider restricting access to the module controller in `SimpleSAMLModule` to minimize the risk of exploitation. Avoid serving content from a case-insensitive file system, such as on Windows, until the issue is resolved.