CVE-2026-2000 Overview
A command injection vulnerability has been identified in DCN DCME-320 devices running firmware versions up to 20260121. The vulnerability exists in the apply_config function within the /function/system/basic/bridge_cfg.php file of the Web Management Backend component. Attackers can exploit this flaw by manipulating the ip_list argument, allowing them to execute arbitrary commands on the affected device remotely.
Critical Impact
Remote attackers with administrative access can inject and execute arbitrary system commands through the web management interface, potentially leading to full device compromise.
Affected Products
- DCN DCME-320 firmware versions up to 20260121
- DCN DCME-320 Web Management Backend component
Discovery Timeline
- 2026-02-06 - CVE-2026-2000 published to NVD
- 2026-02-06 - Last updated in NVD database
Technical Details for CVE-2026-2000
Vulnerability Analysis
This vulnerability is classified as CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), commonly known as injection. The affected component is the web-based management interface of the DCN DCME-320 device, specifically the bridge configuration functionality.
The vulnerability allows authenticated administrators to inject malicious commands through the ip_list parameter. When the apply_config function processes user-supplied input without proper sanitization, the injected commands are executed with the privileges of the web server process. This can enable an attacker to gain unauthorized access to the underlying operating system, modify device configurations, exfiltrate sensitive data, or establish persistent access to the compromised device.
The exploit has been publicly disclosed, and the vendor was contacted early about this issue but did not respond. This lack of vendor response increases the risk for organizations using these devices, as no official patch is currently available.
Root Cause
The root cause of this vulnerability lies in insufficient input validation and sanitization within the apply_config function. The ip_list parameter accepts user-supplied input that is subsequently passed to system command execution functions without proper escaping or validation. This allows specially crafted input containing shell metacharacters to break out of the intended command context and execute arbitrary commands.
Attack Vector
The attack is network-based and requires the attacker to have authenticated access to the web management interface with high privileges. Once authenticated, the attacker can send a malicious HTTP request to /function/system/basic/bridge_cfg.php with a crafted ip_list parameter containing command injection payloads. The injected commands execute on the device with the same privileges as the web server process.
The exploitation mechanism involves injecting shell metacharacters (such as semicolons, pipes, or backticks) followed by malicious commands into the ip_list parameter. When the apply_config function processes this input and constructs a system command, the injected payload is interpreted by the shell, leading to command execution.
Detection Methods for CVE-2026-2000
Indicators of Compromise
- Unusual HTTP POST requests to /function/system/basic/bridge_cfg.php containing shell metacharacters in the ip_list parameter
- Unexpected system processes spawned by the web server process
- Anomalous outbound network connections from the DCME-320 device
- Modified system configurations or new user accounts on the device
Detection Strategies
- Monitor web server access logs for requests to bridge_cfg.php containing suspicious characters such as ;, |, $(), or backticks in parameter values
- Implement web application firewall (WAF) rules to detect and block command injection patterns in HTTP requests
- Deploy network intrusion detection systems (NIDS) with signatures for command injection attempts targeting DCN devices
- Use behavioral analysis to detect unusual command execution patterns on the device
Monitoring Recommendations
- Enable detailed logging on the DCME-320 web management interface and forward logs to a centralized SIEM solution
- Establish baseline network behavior for DCME-320 devices and alert on deviations
- Monitor for unauthorized configuration changes through periodic configuration audits
- Implement file integrity monitoring on critical system files and scripts
How to Mitigate CVE-2026-2000
Immediate Actions Required
- Restrict access to the web management interface to trusted networks only using firewall rules or network segmentation
- Implement strong authentication and limit administrative access to essential personnel
- Consider disabling the web management interface entirely if not operationally required
- Deploy a web application firewall (WAF) in front of the device to filter malicious requests
Patch Information
No official patch is currently available from DCN. The vendor was contacted about this vulnerability but did not respond. Organizations should implement the recommended mitigations and monitor for any future vendor communications or firmware updates. Technical details and proof-of-concept information are available through the GitHub Repository for Routers and VulDB #344548.
Workarounds
- Isolate DCME-320 devices on a dedicated management VLAN with strict access controls
- Implement IP allowlisting to restrict web management interface access to specific administrator workstations
- Use VPN or jump server architecture to access the management interface rather than exposing it directly
- Consider replacing affected devices with alternative solutions from vendors with better security response practices
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
