TCP Gaming

Port 25565 (Minecraft)

Learn about port 25565 (Minecraft) - security risks, vulnerabilities, and common uses. Find devices with port 25565 open.

Quick Info

Port Number

25565

Protocol

TCP

Service

Minecraft

IANA Name

Minecraft

Service Description

Port 25565 (TCP) is the default port used by Minecraft servers. Minecraft, developed by Mojang Studios (now part of Microsoft), is a sandbox video game that allows players to build with a variety of blocks in a 3D world. The server-side application listens on this port to facilitate communication with Minecraft clients. This communication allows players to connect to the server, interact with the game world, and engage in multiplayer activities. The port's widespread use stems directly from the game's popularity and the ease with which users can set up their own dedicated servers.

The protocol used on port 25565 is a custom binary protocol. Clients initiate a handshake by sending a 'Handshake' packet which specifies the protocol version, server address, and the next state (status or login). Following the handshake, the client proceeds either to request server status information (ping) or to initiate the login process. The server responds with the requested status information or proceeds with authentication, which involves verifying the player's account with Mojang's authentication servers. After successful authentication, the player is allowed to join the game world and interact with other players and the environment. The protocol relies heavily on TCP for reliable and ordered delivery of packets, ensuring a consistent game experience.

## Firewall Recommendations

If you are running a Minecraft server, it is necessary to allow inbound TCP traffic on port 25565. However, it's crucial to implement security best practices. Restrict access to only necessary IP addresses or ranges. Employ a firewall to prevent unauthorized access. Keep the Minecraft server software and any installed plugins up to date with the latest security patches. Consider using a reverse proxy to add an extra layer of security and protect against DDoS attacks. If you are not running a Minecraft server, blocking inbound traffic on port 25565 is recommended to reduce your attack surface. Regularly review firewall rules and security logs to identify and mitigate potential threats.

Security Information

Port 25565 is a significant target for attackers due to the popularity of Minecraft and the potential for exploiting vulnerabilities in server implementations or exposed server configurations. Common attack vectors include DDoS attacks aimed at disrupting server availability, exploiting software bugs to gain unauthorized access to the server's file system or execute arbitrary code, and exploiting vulnerabilities in plugins or mods installed on the server. Unpatched servers or improperly configured firewalls can leave the server vulnerable to remote code execution (RCE) exploits, allowing attackers to gain complete control of the server. Furthermore, brute-force attacks targeting weak RCON passwords can grant attackers administrative access to the server.

Known Vulnerabilities

CVE	Name	Severity	Description
CVE-2021-44228	Log4Shell (Log4j)	Critical	Удаленное выполнение кода через уязвимость в библиотеке Log4j, используемой многими серверами Minecraft.
CVE-2017-5941	Spigot Plugin Command Injection	High	Инъекция команд через плагины Spigot, позволяющая удаленное выполнение кода.
CVE-2015-9374	Minecraft Server Information Leak	Medium	Сервер раскрывает информацию о версии и плагинах, что упрощает поиск и эксплуатацию уязвимостей.