CVE-2026-7000: Datacom DM4100 XSS Vulnerability

CVE-2026-7000 Overview

A cross-site scripting (XSS) vulnerability has been identified in Datacom DM4100 network devices running firmware version 1.3.6.1.4.1.3709. The vulnerability exists within the VLAN Page component, where improper sanitization of the VLAN Name argument allows attackers to inject malicious scripts. This vulnerability can be exploited remotely by authenticated users with high privileges, requiring user interaction to trigger the malicious payload.

Critical Impact

Successful exploitation allows attackers to execute arbitrary JavaScript in the context of a victim's browser session, potentially leading to session hijacking, credential theft, or unauthorized actions within the device management interface.

Affected Products

• Datacom DM4100 firmware version 1.3.6.1.4.1.3709

Discovery Timeline

• 2026-04-25 - CVE CVE-2026-7000 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7000

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Cross-Site Scripting), a common web application security flaw where user-supplied input is reflected back to the browser without proper sanitization or encoding. In this case, the VLAN Page component of the Datacom DM4100 administrative interface fails to properly validate and sanitize input provided through the VLAN Name parameter.

The exploit has been publicly disclosed and may be used by attackers. Notably, the vendor was contacted early about this disclosure but did not respond in any way, leaving users without an official patch or guidance.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the VLAN Page component. When administrators configure VLAN names through the device's web interface, the application fails to sanitize special characters that could be interpreted as HTML or JavaScript code. This allows an attacker with administrative access to inject malicious scripts that will execute when other users view the VLAN configuration page.

Attack Vector

The attack requires network access to the device management interface and high-level privileges (administrative access). The attacker must craft a malicious VLAN name containing JavaScript code and save it to the device configuration. When another administrator views the VLAN Page, the malicious script executes in their browser context.

The attack flow typically involves:

1. Attacker gains authenticated access to the DM4100 administrative interface
2. Attacker navigates to the VLAN configuration page
3. Attacker creates or modifies a VLAN entry, injecting script tags or event handlers in the VLAN Name field
4. When a victim administrator views the VLAN Page, the injected script executes in their browser session

Detection Methods for CVE-2026-7000

Indicators of Compromise

• Unusual or suspicious VLAN names containing HTML tags, script elements, or JavaScript event handlers (e.g., <script>, onerror=, onload=)
• Unexpected JavaScript execution or browser behavior when accessing the DM4100 VLAN configuration page
• Reports of session hijacking or unauthorized configuration changes on DM4100 devices

Detection Strategies

• Implement web application firewall (WAF) rules to detect XSS payloads in HTTP requests targeting the VLAN Page endpoint
• Review VLAN configuration entries for suspicious characters or encoded script payloads
• Monitor authentication logs for unusual administrative access patterns to DM4100 devices

Monitoring Recommendations

• Enable detailed logging on the DM4100 management interface to capture configuration changes
• Set up alerts for VLAN configuration modifications, especially those containing special characters
• Conduct regular security audits of network device configurations

How to Mitigate CVE-2026-7000

Immediate Actions Required

• Restrict access to the DM4100 administrative interface to trusted networks and IP addresses only
• Limit administrative access to essential personnel and enforce strong authentication practices
• Review existing VLAN configurations for any suspicious or malicious entries
• Consider placing the device management interface behind a VPN or jump host

Patch Information

No official patch information is available at this time. The vendor was contacted early about this disclosure but did not respond. Users should monitor VulDB Vulnerability #359559 for updates and consider contacting Datacom directly for remediation guidance.

Workarounds

• Implement network segmentation to limit access to the device management interface from untrusted networks
• Use browser-based XSS protection mechanisms and ensure administrators access the interface from hardened browsers
• Consider implementing a reverse proxy with XSS filtering capabilities in front of the management interface
• Conduct regular audits of VLAN names and other user-controllable fields for suspicious content

# Example: Restrict management interface access via firewall rules
# Allow only trusted admin network to access management port
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP