The AT&T U-verse 9.2.2h0d83 firmware for the Arris NVG589 and NVG599 devices, when IP Passthrough mode is not used, configures an unauthenticated proxy service on WAN TCP port 49152, which allows remote attackers to establish arbitrary TCP connections to intranet hosts by sending \x2a\xce\x01 followed by other predictable values.