Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-f8mx-cwfh-7hr2
No affected components available
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.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.
Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Browse More
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard