TCP Messaging

Port 5269 (XMPP Server)

Learn about port 5269 (XMPP Server) - security risks, vulnerabilities, and common uses. Find devices with port 5269 open.

Quick Info

Port Number

5269

Protocol

TCP

Service

XMPP Server

IANA Name

XMPP Server

Service Description

Port 5269 is the standard TCP port used for server-to-server (S2S) communication in the Extensible Messaging and Presence Protocol (XMPP). XMPP is an open, XML-based protocol for real-time communication, including instant messaging, presence information, and multi-party chat. Port 5269 allows XMPP servers to exchange messages and presence information with other XMPP servers, enabling users on different servers to communicate with each other. This federated architecture is a core design principle of XMPP, similar to how email servers communicate. The protocol uses Transport Layer Security (TLS) for encryption to protect the confidentiality and integrity of the exchanged data. The initial connection involves a negotiation phase where the servers exchange XML streams to establish a secure connection. After a connection is established, servers can exchange XML stanzas representing messages, presence updates, and other XMPP data.

The history of port 5269 is tied to the evolution of XMPP, formerly known as Jabber. XMPP was developed in the late 1990s as an open alternative to proprietary instant messaging protocols. The use of port 5269 became standardized as part of the XMPP specifications. The protocol supports various features, including authentication using SASL (Simple Authentication and Security Layer), encryption using TLS/SSL, and the exchange of XML-based messages. The S2S communication relies heavily on XML stanzas, which are structured XML elements representing different types of data. The servers authenticate each other using mechanisms like server-to-server authentication (S2S) with certificates or shared secrets. Proper configuration of DNS records, specifically SRV records, is critical for XMPP servers to discover each other and establish connections on port 5269.

## Firewall Recommendations

Blocking port 5269 will prevent XMPP servers from communicating with each other, effectively isolating the server and preventing users from communicating with users on other XMPP servers. Whether to allow or block this port depends on the intended use of the XMPP server. If federation with other XMPP servers is required, port 5269 must be open. If the server is intended for internal use only and does not need to communicate with external servers, blocking port 5269 can reduce the attack surface. Best practices include: 1. Ensure that the XMPP server software is up to date with the latest security patches. 2. Enforce strong server-to-server authentication mechanisms. 3. Use TLS/SSL with strong ciphers to encrypt all communication on port 5269. 4. Regularly monitor the XMPP server logs for suspicious activity. 5. Implement intrusion detection and prevention systems to detect and block malicious traffic. 6. Consider using a firewall to restrict access to port 5269 to only trusted XMPP servers.

Security Information

Port 5269, being the primary channel for server-to-server XMPP communication, is a significant target for attackers. A compromised server can be used to intercept, modify, or inject malicious messages, potentially leading to data breaches, impersonation, and denial-of-service attacks. Common attack vectors include exploiting vulnerabilities in the XMPP server software, man-in-the-middle attacks if TLS is not properly configured or if weak ciphers are used, and DNS spoofing to redirect traffic to a malicious server. Weak server-to-server authentication mechanisms can also be exploited to impersonate legitimate servers and gain unauthorized access to the XMPP network. A poorly configured or outdated XMPP server can be a stepping stone for attackers to gain access to internal networks or sensitive information. Attackers may target this port to harvest credentials, spread malware, or disrupt communication services.

Known Vulnerabilities

CVE	Name	Severity	Description
CVE-2018-1000021	ejabberd Vulnerability	High	ejabberd before 17.12-RC2 is vulnerable to a cross-site scripting vulnerability. When a user sends a message with malicious HTML code, it is not properly sanitized, resulting in potential XSS attacks.
CVE-2016-1000115	Openfire Vulnerability	Medium	Openfire before 4.0.3 is vulnerable to a reflected XSS vulnerability. The issue occurs when handling error messages, enabling attackers to inject arbitrary web script or HTML via a crafted URL.
CVE-2013-4393	Prosody Vulnerability	Low	Prosody before 0.9.3 allows remote attackers to cause a denial of service (CPU consumption) via a flood of XML stanzas using the stream management feature.
CVE-2016-1000116	Openfire Vulnerability	Medium	Openfire before 4.0.3 is vulnerable to a reflected XSS vulnerability. The issue occurs when handling error messages, enabling attackers to inject arbitrary web script or HTML via a crafted URL.