CVE-2024-31409 Overview
CVE-2024-31409 is an authorization flaw in CyberPower PowerPanel Business for Windows. The system fails to block certain Message Queuing Telemetry Transport (MQTT) wildcards on topic subscriptions. An attacker who gains access to any single device connected to the PowerPanel broker can subscribe to broad topic patterns and harvest data from other devices across the deployment.
The issue maps to [CWE-863: Incorrect Authorization] and is documented in CISA ICS Advisory ICSA-24-123-01. The vulnerability is exploitable over the network without user interaction, though the impact is limited to information disclosure.
Critical Impact
Attackers with access to a single MQTT-connected device can subscribe to wildcard topics and exfiltrate telemetry, status, and configuration data from all devices managed by CyberPower PowerPanel.
Affected Products
- CyberPower PowerPanel Business for Windows
- PowerPanel deployments using the embedded MQTT broker
- Downstream devices publishing telemetry to the PowerPanel MQTT topics
Discovery Timeline
- 2024-05-15 - CVE-2024-31409 published to the National Vulnerability Database (NVD)
- 2024-05-15 - CISA released ICS Advisory ICSA-24-123-01 covering CyberPower PowerPanel
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2024-31409
Vulnerability Analysis
CyberPower PowerPanel uses MQTT as the messaging backbone between the management server and monitored uninterruptible power supply (UPS) devices. MQTT supports two topic wildcards: + matches a single topic level, and # matches all remaining levels. Brokers must enforce access control lists (ACLs) that restrict which clients can subscribe to which topics.
PowerPanel does not filter certain wildcard subscriptions from authenticated clients. A client authorized only for its own topic hierarchy can instead subscribe to patterns such as # or devices/+/telemetry and receive messages intended for every other device. This breaks the tenant isolation model that the broker is expected to enforce.
Root Cause
The root cause is missing authorization checks on wildcard subscription requests. The broker validates connection credentials but does not evaluate whether a subscription pattern would grant a client access to topics outside its permitted scope. The CWE-863 classification reflects this incorrect authorization decision at the subscription-handling layer.
Attack Vector
An attacker first obtains credentials or compromises any device that legitimately connects to the PowerPanel MQTT broker. This can occur through weak device credentials, credential reuse, or lateral movement from another network foothold. After connecting, the attacker issues an MQTT SUBSCRIBE request with a broad wildcard topic. The broker forwards all matching messages, including data from unrelated devices.
Since MQTT payloads in PowerPanel deployments typically contain UPS status, load information, and administrative commands, the attacker can build a complete picture of the environment without triggering additional authentication events. See CISA ICS Advisory ICSA-24-123-01 for vendor-confirmed technical details.
Detection Methods for CVE-2024-31409
Indicators of Compromise
- MQTT SUBSCRIBE packets containing # or multi-level + wildcards originating from device clients that normally publish to a single topic
- Sustained outbound MQTT traffic volumes to clients that historically received only their own telemetry
- Unexpected authenticated sessions from device credentials outside normal maintenance windows
Detection Strategies
- Enable verbose logging on the PowerPanel MQTT broker and alert on subscription patterns that contain wildcards from non-administrative clients
- Baseline per-client subscription topics and flag deviations where a client subscribes to topics it does not own
- Correlate MQTT session logs with endpoint identification telemetry to identify hosts issuing anomalous broker requests
Monitoring Recommendations
- Forward broker logs to a centralized SIEM or data lake and retain subscription events for retrospective hunting
- Monitor network segments carrying MQTT (TCP 1883 or 8883) for volume spikes to individual clients
- Track authentication events for PowerPanel service accounts and device credentials to detect reuse from unexpected hosts
How to Mitigate CVE-2024-31409
Immediate Actions Required
- Update CyberPower PowerPanel Business for Windows to the fixed release listed on the CyberPower Product Downloads Page
- Rotate MQTT credentials used by PowerPanel devices and service accounts after patching
- Restrict network access to the MQTT broker so only authorized management hosts and monitored devices can connect
Patch Information
CyberPower has published updated PowerPanel Business installers that address the wildcard authorization bypass. Administrators should download the current version from the CyberPower Product Downloads Page and follow the upgrade procedure documented in CISA ICS Advisory ICSA-24-123-01.
Workarounds
- Place the PowerPanel MQTT broker on a segmented management VLAN with firewall rules that deny external access
- Configure the broker with explicit ACLs that deny # and multi-level + subscriptions for device-tier accounts where the broker version supports it
- Enforce TLS-encrypted MQTT (port 8883) with client certificates to bind subscriptions to verified device identities
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
