A vulnerability in OPTILINK OP-XT71000N Hardware Version: V2.2 , Firmware Version: OP_V3.3.1-191028 allows an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack to Reset ONU to Factory Default through ' /mgm_dev_reset.asp.' Resetting to default leads to Escalation of Privileges by logging-in with default credentials.