Worked on the openwrt/luci repository to deliver a targeted security fix for modem interface access control lists, focusing on backend development and security. Addressed a command injection vulnerability by expanding the accepted interface number range and replacing unsafe regular expression parsing with fnmatch, aligning with OpenWrt security standards. The solution improved input handling in luci-proto-modemmanager, reducing the risk of unauthorized commands in modem management workflows. Enhanced code maintainability by documenting the rationale and suggesting future improvements. Utilized JSON for configuration and backend logic, ensuring the changes were robust and maintainable while supporting compliance and reliability for OpenWrt deployments.