Cross-site request forgery (CSRF) vulnerability in form2WlanSetup.cgi on Philippine Long Distance Telephone (PLDT) SpeedSurf 504AN devices with firmware GAN9.8U26-4-TX-R6B018-PH.EN and Kasda KW58293 devices allows remote attackers to hijack the authentication of administrators for requests that perform setup operations, as demonstrated by modifying network settings.