CVE-2025-62765: Lynx+ Gateway Information Disclosure Flaw

CVE-2025-62765 Overview

CVE-2025-62765 is a cleartext transmission vulnerability affecting the General Industrial Controls Lynx+ Gateway. The device transmits sensitive data, including authentication credentials, across the network without encryption. An attacker positioned to observe network traffic can capture plaintext credentials and other sensitive information. The flaw is categorized under CWE-319: Cleartext Transmission of Sensitive Information. The vulnerability is network-exploitable with low attack complexity and requires no privileges or user interaction.

Critical Impact
Network-adjacent attackers can passively intercept plaintext credentials transmitted by the Lynx+ Gateway, enabling unauthorized access to industrial control assets.

Affected Products

General Industrial Controls Lynx+ Gateway
Industrial control systems integrating the Lynx+ Gateway
Operational technology (OT) environments exposing the gateway to network traffic interception

Discovery Timeline

2025-11-15 - CVE-2025-62765 published to NVD
2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-62765

Vulnerability Analysis

The Lynx+ Gateway transmits sensitive data over the network in cleartext. Authentication credentials and other sensitive fields traverse the wire without transport-layer encryption such as TLS. Any attacker with the ability to passively observe traffic between the gateway and its clients can recover plaintext credentials. Credential capture can lead to unauthorized administrative access to the gateway and downstream industrial control assets.

The vulnerability impacts confidentiality without requiring authentication, privileges, or user interaction. Because industrial gateways often bridge enterprise and process-control networks, intercepted credentials may also expose connected programmable logic controllers (PLCs), historians, and human-machine interfaces (HMIs).

Root Cause

The root cause is the absence of encryption on protocols carrying authentication and configuration data. The gateway relies on plaintext channels — typical examples in similar OT products include HTTP, Telnet, or unencrypted vendor protocols — rather than TLS, SSH, or other authenticated and encrypted alternatives. This design choice violates secure-by-default principles for transmitting credentials.

Attack Vector

Exploitation requires only network adjacency to a path that carries traffic between the gateway and a legitimate user or system. Attack positions include compromised switches, ARP spoofing within a flat OT segment, span-port abuse, or any wiretap point on the cabling. Once positioned, the attacker performs passive packet capture using standard tools and extracts credentials from the captured streams. No exploit code is required because the data is already in cleartext on the wire.

No public proof-of-concept code is associated with this advisory. Refer to the CISA ICS Advisory ICSA-25-317-08 and the corresponding GitHub CSAF Document for vendor-specific technical details.

Detection Methods for CVE-2025-62765

Indicators of Compromise

Unexpected authentication events on the Lynx+ Gateway originating from non-administrative hosts or unusual subnets.
Presence of ARP spoofing, MAC flooding, or promiscuous-mode interfaces on OT network segments hosting the gateway.
Outbound traffic from engineering workstations to unknown destinations following gateway access.

Detection Strategies

Inspect network traffic to and from the Lynx+ Gateway for cleartext authentication protocols such as HTTP Basic Auth, Telnet, and FTP.
Deploy passive OT network monitoring to baseline normal sessions and alert on credential strings appearing in plaintext payloads.
Correlate gateway logins with workstation activity to identify anomalous source hosts or off-hours access.

Monitoring Recommendations

Mirror traffic from switches serving the Lynx+ Gateway into an intrusion detection system tuned for ICS protocols.
Enable port security and DHCP snooping on OT switches to limit attacker positioning for traffic interception.
Forward gateway authentication logs and switch security events into a centralized SIEM for cross-correlation and long-term retention.

How to Mitigate CVE-2025-62765

Immediate Actions Required

Restrict management access to the Lynx+ Gateway to a dedicated, isolated administrative VLAN with strict access control lists.
Rotate all credentials used with the gateway, assuming prior cleartext exposure on shared network segments.
Disable any unused network services on the gateway to reduce the surface that may transmit cleartext data.

Patch Information

Review the CISA ICS Advisory ICSA-25-317-08 for vendor remediation guidance and any firmware updates published by General Industrial Controls. Apply vendor-supplied patches that introduce encrypted transport for management and authentication traffic as soon as they are available and validated in a test environment.

Workarounds

Place the Lynx+ Gateway behind a VPN or IPsec tunnel so that management traffic is encrypted end-to-end even if the underlying protocol is cleartext.
Segment the gateway into a dedicated OT zone following ISA/IEC 62443 zone and conduit principles, and block management protocols at the perimeter.
Use jump hosts with session recording for administrative access, eliminating direct workstation-to-gateway cleartext sessions.
Monitor and physically secure cabling and switch ports that carry gateway traffic to reduce passive interception risk.

bash

# Example: Restrict gateway management access via firewall rules
# Allow only the admin jump host to reach the Lynx+ Gateway management port
iptables -A FORWARD -s 10.10.50.10/32 -d 10.20.30.40/32 -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d 10.20.30.40/32 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 10.20.30.40/32 -p tcp --dport 23 -j DROP