GHSA-hvm9-wc8j-mgrc
TShock Security Escalation Exploit
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
Impact
An issue with the way OTAPI manages client connections results in stale UUIDs remaining on RemoteClient instances after a player disconnects.
Because of this, if the following conditions are met a player may assume the login state of a previously connected player:
- The server has UUID login enabled
- An authenticated player disconnects
- A subsequent player connects with a modified client that does not send the
ClientUUID#68packet during connection - The server assigns the same
RemoteClientobject that belonged to the originally authenticated player to the newly connected player
Patches
TShock 5.2.1 hotfixes this issue. A more robust fix will be made to OTAPI itself.
Workarounds
Implement a RemoteClient reset event handler in a plugin like so:
public override void Initialize()
{
On.Terraria.RemoteClient.Reset += RemoteClient_Reset;
}
private static void RemoteClient_Reset(On.Terraria.RemoteClient.orig_Reset orig, RemoteClient client)
{
client.ClientUUID = null;
orig(client);
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | TShock | ≥ 4.3.21&&< 5.2.1 | 5.2.1 |
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 5.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hvm9-wc8j-mgrc 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-hvm9-wc8j-mgrc 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-hvm9-wc8j-mgrc. 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-hvm9-wc8j-mgrc in your dependencies?
O3 detects GHSA-hvm9-wc8j-mgrc across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.