[Full-disclosure] (0-Day) GrandStream GXP-2000 VoIP Desktop Phone multiple undocumented UDP ports and DoS

[shawnmer at io.com]

Title:  GrandStream GXP-2000 VoIP Desktop Phone multiple undocumented UDP
ports and DoS

Version: 1.1.0.5

Issues:

1.The phone has multiple undocumented open UDP ports, including 5062,
5064, 5066, 9876, 26789
2.Sending large amount of ascii data via NetCat to any open UDP port,
including UDP/5060, results in the phone either rebooting or placed in a
frozen state, possibly appearing normal (display maintains text, etc.),
except the phone will not be functional.

Credit:

Shawn Merdinger, Independent Security Researcher