Tis

Minecraft 1.19.1-pre2

Mojang has delayed 1.19.1 and released a second pre-release. See the changelog.

Exploits

There are multiple exploits that allow malicious players to forge chat reports that are indistinguishable from real reports. These exploits cannot be fixed with a simple patch. I will release details either when Mojang fixes them or details of the exploits become widely public.

Chat Reports

There are no changes to the chat report format or signatures. As a reminder, chat messages are signed with the sender’s UUID, the current timestmap, and a random salt.

System messages (such as from command blocks) cannot be reported.

Chat Trust Status

The chat trust status indicators are entirely client side and not sent to Mojang.

All player messages over LAN are marked as secure.

If a player chat message is sent with a timestamp over 7 minutes in the past, does not provide a public key, or verification with the public key fails, the message is marked as not secure.

If a player chat message does not contain only signed content, the message is marked as modified. If the show only secure chat option is enabled, then incoming messages will have any unsigned content removed, and the message will be marked as secure as long as there is valid signed content.

System chat messages are marked as unknown security.

If the show only secure chat option is enabled, then messages marked as not secure will not show. System messages will still show.

Servers log expired messages that were sent over 5 minutes in the past but still send them to clients.

Enforce Secure Profile

If enforce-secure-profile is true in server.properties, the server will disconnect the client if the server receives a message with an invalid signature.

Edits

Jul 1 2022

  • Player chat messages expire on the client after 7 minutes, not 2 minutes