GHSA-hvm9-wc8j-mgrc — TShock
Fix: Pryaxis/TShock@5075997GHSA-hvm9-wc8j-mgrc is a security vulnerability in TShock. A fix is available for TShock — see the affected versions and patch details below.
TShock Security Escalation Exploit
Real-World Exposure
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 | 5.2.1dotnet add package TShock --version 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-hvm9-wc8j-mgrc can be triaged on real exposure rather than presence alone.
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 Security finds GHSA-hvm9-wc8j-mgrc across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.