Signature: ET INFO Session Traversal Utilities for NAT (STUN Binding Response)

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Active member
Oct 4, 2020
Does anyone know what this alert means please? I have a Synology Rt2600ac router and have installed the Threat Protection package which inspects every packet coming in and going out to the internet and checks it against Google’s database of discredited IPs and also what the packet is trying to do. The source IP is Amazon and the target is my iPad. What is a user privilege gain? Why should Amazon try to do something to my iPad? The router dropped the packet to no I’ll effect to my iPad 🤷‍♀️

This is the full alert:-

[Threat Prevention] - Suspicious network event Attempted User Privilege Gain dropped
The following suspicious network event was dropped:

Event Type: Attempted User Privilege Gain
Signature: ET INFO Session Traversal Utilities for NAT (STUN Binding Response)
Severity: high
Source IP:
Destination IP:
Time: 2022-10-09 13:23:18 (GMT)
STUN is typically used by telecommunications apps (e.g.: Microsoft Teams, Zoom, FaceTime, VoIP, etc.) to allow “connection” establishment in a NAT and UDP environment.

Normally, it’s your device that will initiate the STUN query to which the responder will confirm the IPv4 address and UDP port in use.

You would need to ask what app you were using at the time.
Further to what @EdwinG said: Source IP: is which is a paid server running in the Amazon cloud. It is presumably a STUN server being referred to by something in your network (app or IoT device.) It may be related to Destination IP: if that IP is not your router.
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