On certain Ubiquiti devices, Command Injection exists via a GET request to stainfo.cgi (aka Show AP info) because the ifname variable is not sanitized, as demonstrated by shell metacharacters. The fixed version is v4.0.1 for 802.11 ISP products, v5.3.5 for AirMax ISP products, and v5.4.5 for AirSync firmware. For example, Nanostation5 (Air OS) is affected.