CVE-2025-6763: Cometsystem T7611 Auth Bypass Vulnerability

CVE-2025-6763 Overview

CVE-2025-6763 is a missing authentication vulnerability [CWE-287, CWE-306] affecting multiple Comet System web-enabled sensor devices running firmware version 1.60. The flaw resides in unspecified functionality of the /setupA.cfg file within the device's Web-based Management Interface. An unauthenticated remote attacker can interact with this resource without providing credentials. The vendor disputes the impact, stating that the affected devices are not intended for direct internet exposure and that securing them is the responsibility of end users. A proof-of-concept exploit has been published, though successful exploitation is rated as high complexity.

Critical Impact

Remote, unauthenticated access to the /setupA.cfg configuration resource on affected Comet System sensors can compromise confidentiality, integrity, and availability of device configuration.

Affected Products

• Comet System T0510, T3510, T3511, T4511, T6640, T7511, T7611 environmental sensors (firmware 1.60)
• Comet System P8510, P8552 industrial transmitters (firmware 4-5-8-0.3488 / 4-5-8-1.3502)
• Comet System H3531 data logger (firmware 9-5-0-1.1327)

Discovery Timeline

• 2025-06-27 - CVE-2025-6763 published to NVD
• 2025-10-08 - Last updated in NVD database

Technical Details for CVE-2025-6763

Vulnerability Analysis

The vulnerability affects the Web-based Management Interface exposed by Comet System sensors and transmitters. The /setupA.cfg endpoint can be accessed without authentication, exposing or allowing manipulation of configuration data that should require administrative credentials. Because the devices function as networked telemetry sensors used in HVAC, server room, and industrial monitoring deployments, configuration tampering can affect downstream alerting and operational decisions.

The issue is classified under both Improper Authentication [CWE-287] and Missing Authentication for Critical Function [CWE-306]. The attack is launched over the network and requires no user interaction, but the advisory notes that exploitation complexity is high, suggesting non-trivial conditions must be met to weaponize the access reliably.

Root Cause

The root cause is the absence of authentication enforcement on the /setupA.cfg resource within the embedded web management interface. The device firmware fails to validate session credentials before serving or accepting requests against this configuration file path, allowing direct access to functionality that should be gated behind administrative login.

Attack Vector

Exploitation is performed remotely over the network against the device's HTTP management interface. An attacker who can reach the device on its management port issues crafted requests to /setupA.cfg to interact with the configuration component without supplying credentials. The vendor emphasizes that these devices are not designed for direct internet exposure, meaning successful exploitation in practice depends on the attacker gaining network adjacency to a deployed sensor.

No verified exploitation code is available for inclusion. A proof-of-concept is referenced in the GitHub PoC Repository and indexed by VulDB #314074.

Detection Methods for CVE-2025-6763

Indicators of Compromise

• Unauthenticated HTTP GET or POST requests to the /setupA.cfg path on Comet System device IP addresses.
• Unexpected modifications to sensor configuration parameters, alarm thresholds, or SNMP/SMTP destinations.
• HTTP access logs on management network segments showing external or unauthorized source addresses contacting Comet device interfaces.

Detection Strategies

• Inventory all Comet System devices on operational networks and confirm firmware versions against the affected list.
• Inspect network flow records for traffic to TCP/80 or TCP/443 of Comet sensors originating outside designated management subnets.
• Deploy IDS signatures that flag HTTP requests targeting /setupA.cfg on networks where Comet devices reside.

Monitoring Recommendations

• Forward network telemetry from operational technology and building management VLANs into a centralized analytics platform for review of Comet device access patterns.
• Alert on configuration drift by periodically polling device configuration and comparing against a known-good baseline.
• Monitor for new external scans probing common Comet System device fingerprints exposed via search engines such as Shodan.

How to Mitigate CVE-2025-6763

Immediate Actions Required

• Remove affected Comet System devices from any internet-reachable interface and place them behind firewall rules restricted to administrative hosts.
• Apply strict network segmentation so the device management interface is only reachable from a dedicated operations VLAN or jump host.
• Audit existing device configurations for unauthorized changes to thresholds, recipients, and network settings.

Patch Information

No vendor patch is referenced in the advisory. The vendor's position is that the affected devices are not intended for internet exposure and that securing them is the responsibility of end users. Operators should monitor the Comet System support channels and VulDB #314074 for updated firmware availability.

Workarounds

• Enforce IP allowlisting on upstream firewalls so only designated administrative workstations can reach the device web interface.
• Place devices behind a reverse proxy that requires authentication before forwarding requests to the device.
• Disable the web management interface on devices when not in active use, and rely on SNMP or Modbus over restricted segments for telemetry collection.
• Use a VPN or jump host for any remote administrative access to Comet System sensors.