GHSA-f8mx-cwfh-7hr2
TShock allows chat while not fully connected, possible ban evasion
Blast Radius
TShockReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
This issue was reported to TShock by @ohayo, but was found by the Discord user by the name of sofurry.com. Please note that this user does not own this domain on the internet, just the discord handle.
TShock overrides certain Terraria vanilla systems, including chat, and the connection handling, for its own purposes, like enforcing bans. When clients connect but do not complete the connection handshake (e.g., send message number 6), they can "exist" on the server, occupy a player slot, chat, and receive data from the server despite not being fully connected. Individuals who exploit this will be able to effectively harass the server, observe the server, and utilize server resources even if banned from the server.
For servers that operate with a proxy that strictly enforces the connection handshake/sequence, this is not an issue, but for smaller servers or servers running vanilla TShock this is an issue worth patching for.
PR body supplied by @ohayo (patch writer):
Terraria's standard server by default checks for bans upon the client sending the ConnectRequest packet, however, TShock instead chooses to check if the client connecting is banned upon the Request World Data packet.
A malicious client can easily just not send this packet, and still join the server even while being banned. Also by not sending Request World Data, the malicious client is still able to receive all packets from the server & even chat.
Other clients will not be notified of their join/leave but will be able to see them on the player list. Leading to potential chat spam & "spying" on packets of players within the server.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | TShock | all versions | 5.2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for TShock. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update TShock to 5.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f8mx-cwfh-7hr2 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-f8mx-cwfh-7hr2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f8mx-cwfh-7hr2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f8mx-cwfh-7hr2 in your dependencies?
O3 detects GHSA-f8mx-cwfh-7hr2 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.