Name of the Vulnerable Software and Affected Versions: PocketMine-MP (affected versions not specified)

Description: The issue arises from the way operator permissions are checked using the Config->exists() function with lowercase=true. This allows a user to add their name to the ops.txt file with uppercase letters, making it impossible to remove their operator permissions using commands.

Recommendations: To address this issue, remove the offending lines from ops.txt manually. At the moment, there is no information about a newer version that contains a fix for this vulnerability.