Cross-site request forgery (CSRF) vulnerability on BUFFALO BHR-4GRV2 devices with firmware 1.04 and earlier, WEX-300 devices with firmware 1.90 and earlier, WHR-1166DHP devices with firmware 1.90 and earlier, WHR-300HP2 devices with firmware 1.90 and earlier, WHR-600D devices with firmware 1.90 and earlier, WMR-300 devices with firmware 1.90 and earlier, WMR-433 devices with firmware 1.01 and earlier, and WSR-1166DHP devices with firmware 1.01 and earlier allows remote attackers to hijack the authentication of arbitrary users.