CVE-2025-41276: Waterfall WF-500 Firmware RCE Vulnerability

CVE-2025-41276 Overview

CVE-2025-41276 is an OS command injection vulnerability [CWE-78] in the Console WebUI of Waterfall Security WF-500 TX and RX Hosts. Nozomi Networks Labs identified the flaw in firmware version 7.9.1.0 R2502171040. The vulnerability allows remote, unauthenticated attackers to execute arbitrary operating system commands on the affected device. Waterfall WF-500 systems are deployed as unidirectional security gateways in industrial and operational technology environments, where compromise can disrupt segmentation between IT and OT networks.

Critical Impact
Unauthenticated remote attackers can execute arbitrary OS commands on Waterfall WF-500 devices through the Console WebUI, undermining the integrity of unidirectional gateway deployments.

Affected Products

Waterfall Security WF-500 TX Host firmware version 7.9.1.0 R2502171040
Waterfall Security WF-500 RX Host firmware version 7.9.1.0 R2502171040
Waterfall Security WF-500 hardware appliance running the affected firmware

Discovery Timeline

2026-05-29 - CVE-2025-41276 published to NVD
2026-06-01 - Last updated in NVD database

Technical Details for CVE-2025-41276

Vulnerability Analysis

The Console WebUI of the Waterfall WF-500 TX and RX Hosts fails to neutralize special elements passed into operating system commands. An attacker reaching the WebUI over the network can inject shell metacharacters into a vulnerable parameter, causing the underlying operating system to execute attacker-supplied commands.

No authentication is required to reach the vulnerable endpoint. The attack vector is network-based with low attack complexity and no user interaction. Successful exploitation yields confidentiality, integrity, and availability impact on the device.

The WF-500 functions as a unidirectional security gateway between segmented networks. Code execution on either the TX or RX host can be leveraged to tamper with replicated data flows, exfiltrate configuration, or pivot deeper into the connected environments. EPSS data places the exploitation probability at 0.368% (percentile 59.006) as of June 2026, with no public proof-of-concept yet observed.

Root Cause

The root cause is improper neutralization of special elements ([CWE-78]) within a Console WebUI handler that builds and executes an OS command string using attacker-controlled input. Input from the HTTP request is concatenated into the command without sanitization, escaping, or use of an argument-vector API, allowing shell metacharacters such as ;, |, &, and backticks to break out of the intended command context.

Attack Vector

The attacker sends a crafted HTTP request to the Console WebUI exposed by the WF-500 TX or RX host. Because the endpoint does not enforce authentication, any network-reachable client can submit the malicious payload. The injected payload is passed unsanitized to a shell, where it executes with the privileges of the WebUI process. Exploitation requires only network reachability to the management interface, making perimeter exposure and flat OT management networks especially high-risk deployment patterns.

No verified proof-of-concept code is publicly available. Refer to the Nozomi Networks Vulnerability Advisory for additional technical context.

Detection Methods for CVE-2025-41276

Indicators of Compromise

Unexpected child processes (for example sh, bash, nc, wget, curl) spawned by the Console WebUI service on WF-500 hosts.
HTTP requests to the Console WebUI containing shell metacharacters such as ;, |, &&, backticks, or $() in parameter values.
Outbound network connections originating from the WF-500 management interface to unfamiliar IP addresses.
New or modified files in writable directories used by the WebUI process, indicating dropped tooling or persistence.

Detection Strategies

Monitor WF-500 management interface HTTP access logs for anomalous query strings and POST bodies containing command separators.
Alert on any process execution by the WebUI service that is not part of its documented runtime behavior.
Inspect north-south and east-west traffic to the WF-500 management VLAN for unauthorized sources reaching the Console WebUI.

Monitoring Recommendations

Forward WF-500 syslog, web server, and authentication logs to a centralized SIEM or data lake for correlation with network telemetry.
Baseline normal administrative activity on the Console WebUI and alert on deviations such as off-hours access or non-administrator source IPs.
Capture full packet metadata at the OT-IT boundary so that suspected exploitation attempts can be reconstructed for forensic review.

How to Mitigate CVE-2025-41276

Immediate Actions Required

Restrict network access to the Console WebUI to a dedicated management network and a small set of administrator workstations.
Place the WF-500 management interface behind a jump host that enforces multi-factor authentication and full session logging.
Inventory all WF-500 TX and RX hosts and confirm which are running firmware 7.9.1.0 R2502171040 or earlier.
Review WebUI access logs for indicators of exploitation predating the patch deployment.

Patch Information

Waterfall Security has published remediation guidance through the coordinated disclosure with Nozomi Networks Labs. Operators should consult the Nozomi Networks Vulnerability Advisory and contact Waterfall Security support to obtain the fixed firmware build for both TX and RX hosts. Apply the update to all affected appliances and verify the running firmware version after upgrade.

Workarounds

Block inbound access to the Console WebUI TCP port at upstream firewalls until the firmware update is applied.
Disable or shut down the Console WebUI service on appliances where management is performed exclusively through alternative channels.
Apply ACLs on switches and routers to permit Console WebUI access only from explicitly authorized management addresses.
Increase monitoring frequency on WF-500 hosts and adjacent OT network segments during the interim mitigation period.

bash

# Example: restrict Console WebUI access to a single management subnet
# (apply on the upstream firewall protecting the WF-500 management VLAN)
iptables -A FORWARD -p tcp -s 10.10.50.0/24 -d <wf500_mgmt_ip> --dport 443 -j ACCEPT
iptables -A FORWARD -p tcp -d <wf500_mgmt_ip> --dport 443 -j DROP