Collected research

TURN server allows TCP and UDP proxying to internal network

Slack disclosed on HackerOne: TURN server allows TCP and UDP...

Slack's TURN relay accepted ChannelBind and CreatePermission requests for private and special-use addresses, letting anyone with relay credentials proxy TCP connections and UDP packets into the internal network, to localhost and to the AWS metadata service. The reach is SSRF-like but not limited to HTTP, so internal DNS and other UDP services could be scanned and queried.

Record

Document

Slack disclosed on HackerOne: TURN server allows TCP and UDP...

Published by

HackerOne

Topic

HTTP

In the archive

• Collected in the 2020 research round

Tags

• ssrf
• webrtc
• proxy
• dns
• aws
• info-leak
• bug-bounty
• case-study
• owasp-a10-2021

This page is the archive's own catalogue record. The research is the work of HackerOne, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 9 August 2026.