CVE-2025-52136 in EMQX
Summary
by MITRE • 08/10/2025
In EMQX before 5.8.6, administrators can install arbitrary novel plugins via the Dashboard web interface. NOTE: the Supplier's position is that this is the intended behavior; however, 5.8.6 adds a defense-in-depth feature in which a plugin's acceptability (for later Dashboard installation) is set by the "emqx ctl plugins allow" CLI command.
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Analysis
by VulDB Data Team • 08/10/2025
The vulnerability CVE-2025-52136 affects EMQX versions prior to 5.8.6 and represents a significant security concern related to plugin management within the dashboard interface. This issue stems from the absence of proper validation mechanisms that would normally restrict which plugins can be installed through the web-based administrative interface. The flaw allows any administrator with access to the dashboard to install novel plugins without restriction, potentially enabling unauthorized code execution or privilege escalation within the messaging infrastructure. This behavior creates an attack surface that could be exploited by malicious actors who gain administrative access or by insiders with elevated privileges. The vulnerability directly impacts the principle of least privilege and could lead to complete system compromise if attackers can leverage this functionality to deploy malicious plugins that bypass normal security controls.
The technical implementation flaw lies in the lack of plugin acceptance validation within the dashboard web interface. Prior to version 5.8.6, the system trusted administrators to make appropriate plugin selection decisions without implementing any form of approval or verification mechanism. This represents a failure in defense-in-depth principles and violates the concept of secure by default configurations. The vulnerability can be categorized under CWE-494 as "Download of Code Without Integrity Check" and aligns with ATT&CK technique T1106 for "Execution of File" and T1059 for "Command and Scripting Interpreter" when malicious plugins are installed. The absence of proper input validation and access controls creates a path for arbitrary code execution through the plugin installation process, potentially allowing attackers to modify core system functionality or establish persistence within the messaging environment.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise potential. Administrators with dashboard access could install plugins that modify message routing, intercept communications, or provide backdoor access to the messaging infrastructure. This risk is particularly severe in environments where dashboard access is not adequately restricted or where multiple administrative users exist. The vulnerability could enable attackers to establish persistent access points within the messaging system, potentially affecting thousands of connected IoT devices or applications that rely on EMQX for message brokering. Organizations using EMQX in production environments face the risk of data exfiltration, service disruption, or complete system takeover through this vector. The impact is amplified when considering that many IoT and edge computing deployments rely heavily on such messaging systems for critical operations.
The vendor addressed this vulnerability through the introduction of a defense-in-depth mechanism in EMQX 5.8.6, specifically the "emqx ctl plugins allow" CLI command that controls plugin acceptability for dashboard installation. This approach aligns with the principle of least privilege and provides administrators with explicit control over which plugins can be installed through the web interface. The solution demonstrates proper security engineering by implementing a two-factor approval process where plugins must first be explicitly allowed via command line before they can be installed through the dashboard. Organizations should immediately upgrade to EMQX 5.8.6 or later versions to remediate this vulnerability. Additional mitigations include restricting dashboard access to trusted administrative users, implementing network segmentation around the messaging infrastructure, and conducting regular security audits of installed plugins. The vulnerability also highlights the importance of maintaining updated security configurations and the necessity of implementing proper access controls for administrative interfaces to prevent unauthorized plugin installations and maintain system integrity.