CVE-2025-27455: Endress Meac300 Clickjacking Vulnerability

CVE-2025-27455 Overview

CVE-2025-27455 is a clickjacking vulnerability affecting the Endress MEAC300-FNADE4 firmware web application. The application fails to set framing restrictions, allowing the site to be embedded inside an attacker-controlled <iframe>. An attacker can overlay the framed page and trick an authenticated user into clicking hidden interface elements. This user interface redress attack can lead to unauthorized actions, disclosure of configuration data, or manipulation of device controls. The weakness is tracked as [CWE-1021] Improper Restriction of Rendered UI Layers or Frames.

Critical Impact
An authenticated user visiting an attacker-controlled page can be tricked into executing unintended actions on the MEAC300-FNADE4 device, resulting in limited confidentiality and integrity impact with a scope change.

Affected Products

Endress MEAC300-FNADE4 firmware (all versions per vendor advisory)
Endress MEAC300-FNADE4 hardware appliance
Systems exposing the MEAC300-FNADE4 web management interface

Discovery Timeline

2025-07-03 - CVE-2025-27455 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-27455

Vulnerability Analysis

The MEAC300-FNADE4 web application does not enforce anti-framing protections on its HTTP responses. Browsers therefore permit third-party origins to load the management interface inside a frame, iframe, object, or embed element. An attacker hosts a malicious page that loads the target console and stacks transparent controls above it. When an authenticated administrator interacts with the visible decoy, clicks are delivered to the underlying MEAC300-FNADE4 interface. The attack requires user interaction and a valid active session in the victim's browser. The scope change reflected in the CVSS vector indicates that exploitation affects resources beyond the vulnerable component, since the attacker's origin controls a session belonging to the device.

Root Cause

The root cause is missing HTTP response headers that instruct the browser to reject framing. The application does not return X-Frame-Options: DENY or SAMEORIGIN, nor does it emit a Content-Security-Policy header containing a frame-ancestors directive. Without these controls, the browser applies its default behavior and renders the page inside any parent frame regardless of origin.

Attack Vector

Exploitation is network-based and requires user interaction. The attacker must persuade an authenticated MEAC300-FNADE4 operator to visit an attacker-controlled web page. The attacker page embeds the device management URL in an iframe, layers deceptive UI elements over sensitive controls, and captures clicks or keystrokes routed to the framed page. Typical outcomes include triggering configuration changes, submitting forms, or revealing on-screen data. See the SICK CSAF PDF Advisory for vendor-supplied technical detail.

No verified public proof-of-concept is available. The vulnerability mechanism is described in prose because no vetted exploit code has been published.

Detection Methods for CVE-2025-27455

Indicators of Compromise

Web server access logs showing MEAC300-FNADE4 management pages loaded with a Referer header pointing to unfamiliar external domains.
Browser telemetry recording the device URL rendered within a cross-origin frame.
Unexpected configuration changes or form submissions from operator sessions with no corresponding direct navigation event.

Detection Strategies

Inspect HTTP responses from the device for the absence of X-Frame-Options and Content-Security-Policy: frame-ancestors headers.
Correlate operator authentication events with referrer data to identify sessions driven from external origins.
Deploy content security policy reporting endpoints to capture attempted framing violations from monitored browsers.

Monitoring Recommendations

Alert on outbound HTTP requests from operator workstations that load the MEAC300-FNADE4 interface with a foreign Referer.
Track administrative actions on the device and require out-of-band confirmation for configuration changes.
Monitor firewall and proxy logs for operator browsers contacting untrusted domains shortly before device configuration events.

How to Mitigate CVE-2025-27455

Immediate Actions Required

Restrict network access to the MEAC300-FNADE4 management interface so only trusted engineering workstations can reach it.
Instruct operators to log out of the device console when it is not in active use to invalidate session cookies.
Segment the device onto an isolated OT network in line with CISA ICS Recommended Practices.

Patch Information

Consult the vendor advisory published through the SICK PSIRT Overview and the machine-readable SICK CSAF JSON Advisory for firmware update availability and remediation guidance specific to the MEAC300-FNADE4 platform.

Workarounds

Place the management interface behind a reverse proxy that appends X-Frame-Options: DENY and Content-Security-Policy: frame-ancestors 'none' to every response.
Require operators to use a dedicated browser profile with strict site isolation and no unrelated browsing activity.
Enforce browser policies that block third-party framing of the device's hostname.

bash

# Configuration example: nginx reverse proxy adding anti-framing headers
server {
    listen 443 ssl;
    server_name meac300.internal.example;

    location / {
        proxy_pass https://meac300-device.local;
        proxy_set_header Host $host;

        add_header X-Frame-Options "DENY" always;
        add_header Content-Security-Policy "frame-ancestors 'none'" always;
    }
}