An issue in DrayTek Vigor310 devices through 4.3.2.6 allows an attacker to obtain sensitive information because the httpd server of the Vigor management UI uses a static string for seeding the PRNG of OpenSSL.

DrayTek Vigor310 devices through 4.3.2.6 allow a remote attacker to execute arbitrary code via the function ft_payload_dns(), because a byte sign-extension operation occurs for the length argument of a _memcpy call, leading to a heap-based Buffer Overflow.

DrayTek Vigor3910 devices through 4.3.2.6 allow unauthenticated DOM-based reflected XSS.

Stored XSS, by authenticated users, is caused by poor sanitization of the Login Page Greeting message in DrayTek Vigor310 devices through 4.3.2.6.

Draytek Vigor Routers firmware versions below 3.9.6/4.2.4, Access Points firmware versions below v1.4.0, Switches firmware versions below 2.6.7, and Myvigor firmware versions below 2.3.2 were discovered to use hardcoded encryption keys which allows attackers to bind any affected device to their own account. Attackers are then able to create WCF and DrayDDNS licenses and synchronize them from the website.

An issue was discovered on certain DrayTek Vigor routers before July 2022 such as the Vigor3910 before 4.3.1.1. /cgi-bin/wlogin.cgi has a buffer overflow via the username or password to the aa or ab field.