Sensitive File Protection Bypass - Path Manipulation Using Backslashes on Windows

Summary

Cursor correctly detects path manipulation via forward slashes (./.cursor/./././././mcp.json etc.), and requires human approval to complete the operation. However, the same kind of manipulation using backslashes was not correctly detected, allowing an attacker who had already achieved prompt injection or some other level of control to overwrite sensitive editor files without approval on windows machines.

Impact

Manipulating internal settings may lead to RCE. Must be chained with a prompt injection or malicious model. Only affects Windows.

Remediation

Parsing is not done correctly based on the underlying platform.