CVE-2026-24455: Web Interface Information Disclosure Flaw

CVE-2026-24455 Overview

CVE-2026-24455 is a cleartext transmission vulnerability affecting embedded web interfaces of industrial control system devices. The vulnerability exists because the device's web interface does not support HTTPS/TLS for authentication and instead relies on HTTP Basic Authentication. While traffic is encoded, it is not encrypted, exposing user credentials to passive interception by attackers on the same network.

This vulnerability falls under CWE-319 (Cleartext Transmission of Sensitive Information), representing a significant risk in operational technology (OT) environments where credential theft could lead to unauthorized access to critical infrastructure systems.

Critical Impact

User credentials transmitted via HTTP Basic Authentication can be intercepted by network attackers, potentially leading to unauthorized access to industrial control systems and operational technology infrastructure.

Affected Products

• Embedded web interface devices (specific product details available in CISA advisory)
• Industrial control system (ICS) devices with web-based management interfaces
• OT devices utilizing HTTP Basic Authentication

Discovery Timeline

• 2026-02-20 - CVE-2026-24455 published to NVD
• 2026-02-20 - Last updated in NVD database

Technical Details for CVE-2026-24455

Vulnerability Analysis

This vulnerability represents a fundamental security design flaw in the implementation of authentication for embedded web interfaces. HTTP Basic Authentication transmits credentials using Base64 encoding, which is trivially decoded and provides no confidentiality protection. Without TLS/HTTPS encryption, any network observer positioned between the user and the device can capture and decode these credentials in real-time.

The attack is classified as a network-based attack requiring no privileges or user interaction to exploit. An attacker with passive network access on the same network segment can monitor traffic and extract credentials without alerting the user or the device. This is particularly concerning in industrial environments where network segmentation may be limited and devices often retain default or shared credentials.

Root Cause

The root cause of CVE-2026-24455 is the absence of transport layer security (TLS/HTTPS) implementation in the embedded web interface combined with the use of HTTP Basic Authentication. HTTP Basic Authentication was designed for simple authentication scenarios and explicitly requires TLS to provide confidentiality. The device manufacturer failed to implement HTTPS support, leaving credential transmission vulnerable to passive eavesdropping attacks.

Attack Vector

An attacker positioned on the same network segment as the target device can exploit this vulnerability through passive network traffic capture. The attack does not require any special privileges, authentication, or user interaction. Using common network analysis tools, an attacker can capture HTTP traffic destined for the device's web interface, extract the Base64-encoded Authorization header, and decode it to obtain plaintext credentials.

The exploitation process involves:

1. Gaining access to the same network segment as the vulnerable device
2. Initiating passive network traffic capture targeting HTTP traffic on the device's port
3. Waiting for a legitimate user to authenticate to the web interface
4. Extracting the HTTP Authorization header from captured traffic
5. Decoding the Base64 credentials to obtain username and password

This attack is entirely passive and leaves no evidence on the target device, making it difficult to detect through device-based monitoring alone.

Detection Methods for CVE-2026-24455

Indicators of Compromise

• HTTP traffic containing Authorization headers observed on network segments hosting vulnerable devices
• Unusual or unauthorized login attempts to device web interfaces following network reconnaissance activity
• Multiple authentication attempts from IP addresses not associated with authorized administrators

Detection Strategies

• Deploy network monitoring to identify unencrypted HTTP traffic with Basic Authentication headers on OT network segments
• Implement network intrusion detection rules to alert on HTTP Basic Authentication traffic to known vulnerable devices
• Audit network traffic logs for HTTP connections to embedded device management interfaces

Monitoring Recommendations

• Enable logging on network infrastructure devices to capture connection metadata for embedded device management interfaces
• Implement out-of-band network monitoring on segments containing vulnerable OT devices
• Review authentication logs on upstream systems for credential reuse attempts that may indicate prior interception

How to Mitigate CVE-2026-24455

Immediate Actions Required

• Isolate vulnerable devices on dedicated network segments with strict access controls
• Implement network-level encryption such as VPN tunnels for all administrative access to affected devices
• Restrict web interface access to trusted management workstations only
• Review and rotate credentials for all affected devices immediately

Patch Information

Consult the CISA ICS Advisory ICSA-26-050-03 for vendor-specific patch information and firmware updates that may address this vulnerability. Additional technical details are available in the GitHub CSAF JSON File.

Workarounds

• Deploy a reverse proxy with TLS termination in front of the vulnerable device's web interface
• Implement network segmentation to isolate vulnerable devices from general network traffic
• Use VPN connections for all administrative access to affected devices
• Configure firewall rules to restrict access to the web interface to specific management IP addresses only
• Consider disabling the web interface entirely if alternative management methods are available

# Example: Restrict web interface access using iptables
# Allow only specific management workstation
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
# Block all other access to HTTP interface
iptables -A INPUT -p tcp --dport 80 -j DROP