An issue was discovered on Linksys WRT1900ACS 1.0.3.187766 devices. A lack of encryption in how the user login cookie (admin-auth) is stored on a victim\'s computer results in the admin password being discoverable by a local attacker, and usable to gain administrative access to the victim\'s router. The admin password is stored in base64 cleartext in an "admin-auth" cookie. An attacker sniffing the network at the time of login could acquire the router\'s admin password. Alternatively, gaining physical access to the victim\'s computer soon after an administrative login could result in compromise.