CVE-2024-3871: Delta Electronics DVW-W02W2-E2 RCE Flaw

CVE-2024-3871 Overview

CVE-2024-3871 is a critical vulnerability affecting Delta Electronics DVW-W02W2-E2 industrial network devices. The affected devices expose a web administration interface that contains multiple security flaws, including command injection and stack overflow vulnerabilities. These flaws exist in various features implemented within the web interface, allowing attackers to inject malicious commands or trigger memory corruption conditions.

Successful exploitation of these vulnerabilities would allow remote unauthenticated attackers to gain remote code execution with elevated privileges on the affected devices. Given the industrial nature of these devices and their potential deployment in critical infrastructure environments, this vulnerability poses a significant security risk.

Critical Impact

Remote unauthenticated attackers can achieve full system compromise with elevated privileges through command injection or stack overflow exploitation in the web administration interface.

Affected Products

• Delta Electronics DVW-W02W2-E2 firmware through version 2.5.2
• All devices running vulnerable firmware versions with exposed web administration interfaces

Discovery Timeline

• April 16, 2024 - CVE-2024-3871 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-3871

Vulnerability Analysis

This vulnerability is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command - Command Injection). The Delta Electronics DVW-W02W2-E2 web administration interface fails to properly sanitize user-supplied input before passing it to system command execution functions. Additionally, the interface contains stack-based buffer overflow conditions where input length is not properly validated before being copied to fixed-size stack buffers.

The combination of command injection and stack overflow vulnerabilities provides attackers with multiple exploitation paths. Command injection allows direct execution of arbitrary system commands, while stack overflow conditions can be leveraged to overwrite return addresses and redirect program execution flow.

Root Cause

The root cause of these vulnerabilities stems from insufficient input validation and sanitization in the web administration interface. Specifically:

1. Command Injection: User-controlled input is directly incorporated into shell commands without proper escaping or sanitization of special characters (such as ;, |, &, backticks, and $() constructs).

2. Stack Overflow: Input buffers are copied to fixed-size stack allocations without proper bounds checking, allowing attackers to supply oversized input that overwrites adjacent stack memory, including return addresses.

These flaws indicate a systemic lack of secure coding practices in the firmware development, particularly around handling untrusted user input in a privileged context.

Attack Vector

The attack vector is network-based, requiring no authentication or user interaction. An attacker with network access to the device's web administration interface can craft malicious HTTP requests targeting vulnerable endpoints. The attack can be executed remotely from anywhere on the network where the web interface is accessible.

Command injection attacks typically involve injecting shell metacharacters and commands into input fields or URL parameters that are processed by backend scripts. Stack overflow attacks require carefully crafted payloads that overflow the target buffer and overwrite the return address with attacker-controlled values, potentially redirecting execution to injected shellcode or ROP gadgets.

The vulnerability is particularly severe because exploitation grants elevated privileges, suggesting the web interface runs with root or equivalent system-level permissions.

Detection Methods for CVE-2024-3871

Indicators of Compromise

• Unusual outbound network connections from DVW-W02W2-E2 devices to unknown external IP addresses
• Unexpected processes or services running on affected devices
• Anomalous HTTP requests to the web administration interface containing shell metacharacters (;, |, &, backticks) or unusually long parameter values
• Log entries indicating authentication failures followed by successful command execution
• Modified system files or new user accounts on the affected devices

Detection Strategies

• Deploy network intrusion detection systems (IDS) with signatures for command injection patterns targeting industrial devices
• Monitor HTTP traffic to DVW-W02W2-E2 devices for requests containing shell metacharacters or excessively long input values
• Implement anomaly detection for network traffic patterns from industrial IoT devices
• Review web server access logs on affected devices for suspicious request patterns
• Utilize SentinelOne Singularity Platform for endpoint detection and response on network segments containing vulnerable devices

Monitoring Recommendations

• Segment DVW-W02W2-E2 devices from general network traffic and monitor all communications
• Implement strict network access controls limiting which hosts can communicate with the web administration interface
• Enable comprehensive logging on affected devices and forward logs to a centralized SIEM for analysis
• Monitor for firmware integrity changes using file integrity monitoring solutions
• Set up alerts for any new network connections initiated by these devices

How to Mitigate CVE-2024-3871

Immediate Actions Required

• Restrict network access to the web administration interface using firewall rules or network segmentation
• Disable the web administration interface if not required for operations
• Implement network-level access controls allowing only trusted administrator IP addresses to reach the interface
• Monitor affected devices for signs of compromise using the detection methods outlined above
• Contact Delta Electronics for updated firmware information and patch availability

Patch Information

Organizations should check with Delta Electronics directly for firmware updates that address these vulnerabilities. At the time of publication, users are advised to review the OneKey Security Overview for additional security information related to this vulnerability.

Affected firmware versions include all releases through version 2.5.2. Ensure any updated firmware is obtained directly from Delta Electronics or authorized distribution channels to avoid supply chain risks.

Workarounds

• Place affected devices behind a dedicated firewall with strict ingress rules allowing only essential traffic
• Implement VPN requirements for any remote administration access to affected devices
• Use network access control lists (ACLs) to whitelist specific administrator workstations
• Deploy a web application firewall (WAF) in front of the device to filter malicious requests
• If possible, disable the web interface entirely and use alternative management methods

# Example firewall rule to restrict web interface access (adapt to your firewall)
# Allow only trusted admin subnet to access web interface
iptables -A INPUT -p tcp --dport 80 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP