Loytec LINX firmware: Improper Authentication in PAM configuration

Improper Authentication (CWE-287) in the PAM configuration in Loytec LIP-ME201C, L-INX, L-GATE, L-ROC, L-IOB, L-DALI, L-VIS and L-PAD through 8.4.16 on LINX-A64 allows a local attacker to authenticate as a uid=0 account without a password and obtain a root shell via an /etc/passwd entry with an empty password field.