An issue was discovered on Systrome Cumilon ISG-600C, ISG-600H, and ISG-800W devices with firmware V1.1-R2.1_TRUNK-20181105.bin. A shell command injection occurs by editing the description of an ISP file. The file network/isp/isp_update_edit.php does not properly validate user input, which leads to shell command injection via the des parameter.