CVE-2023-23333: SolarView Compact Firmware RCE Vulnerability

CVE-2023-23333 Overview

CVE-2023-23333 is a command injection vulnerability affecting Contec SolarView Compact firmware through version 6.00. This vulnerability allows remote attackers to execute arbitrary operating system commands by exploiting weaknesses in the downloader.php endpoint, effectively bypassing internal restrictions implemented by the application.

Critical Impact

Remote unauthenticated attackers can achieve full system compromise by injecting and executing arbitrary commands on affected SolarView Compact devices, potentially leading to complete control over solar monitoring infrastructure.

Affected Products

• Contec SolarView Compact Firmware through version 6.00
• Contec SolarView Compact hardware devices

Discovery Timeline

• 2023-02-06 - CVE-2023-23333 published to NVD
• 2025-03-26 - Last updated in NVD database

Technical Details for CVE-2023-23333

Vulnerability Analysis

This command injection vulnerability (CWE-77) exists in the SolarView Compact web interface, specifically within the downloader.php script. The vulnerability allows attackers to bypass internal security restrictions that were intended to prevent command execution. The flaw stems from insufficient input validation and sanitization of user-supplied data before it is passed to system shell functions.

SolarView Compact is a solar power monitoring system used in industrial and commercial environments. The exploitation of this vulnerability could allow attackers to gain unauthorized access to these systems, potentially disrupting solar power monitoring operations or using compromised devices as a foothold for further network penetration.

Root Cause

The root cause of CVE-2023-23333 lies in improper input validation within the downloader.php endpoint. User-controlled input is not adequately sanitized before being incorporated into system commands, allowing attackers to inject malicious shell metacharacters and commands. The internal restrictions meant to prevent such abuse can be bypassed, enabling direct command execution on the underlying operating system.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker can craft malicious HTTP requests to the downloader.php endpoint, embedding shell commands within parameters that are subsequently executed by the server. This allows for remote command execution without any prior access to the system.

The vulnerability can be exploited by sending specially crafted requests that include shell metacharacters (such as semicolons, pipes, or backticks) to break out of the intended command context and execute arbitrary commands. Technical details and proof-of-concept information are available through the Packet Storm Security Advisory and the GitHub CVE-2023-23333 Repository.

Detection Methods for CVE-2023-23333

Indicators of Compromise

• Unusual HTTP requests to downloader.php containing shell metacharacters such as ;, |, &, `, or $() in URL parameters
• Unexpected outbound network connections from SolarView Compact devices
• Creation of new files or modification of system files on the device
• Evidence of reverse shell connections or command-and-control traffic originating from the device

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing command injection patterns targeting downloader.php
• Monitor HTTP access logs for suspicious requests to the vulnerable endpoint with encoded or unencoded shell metacharacters
• Deploy network intrusion detection signatures to identify exploitation attempts against SolarView Compact devices
• Use SentinelOne Singularity to detect anomalous process execution on devices where agents can be deployed

Monitoring Recommendations

• Establish baseline network behavior for SolarView Compact devices and alert on deviations
• Monitor for unexpected DNS queries or network connections from solar monitoring infrastructure
• Log and analyze all web requests to the management interface of SolarView Compact devices
• Implement egress filtering to detect and block potential reverse shell communications

How to Mitigate CVE-2023-23333

Immediate Actions Required

• Restrict network access to SolarView Compact management interfaces using firewall rules to allow only trusted IP addresses
• Isolate affected devices on a separate network segment with no direct internet access
• Disable or remove the downloader.php script if it is not essential for operations
• Monitor affected systems for signs of compromise while awaiting a firmware update from Contec

Patch Information

Organizations should contact Contec directly for information regarding firmware updates that address CVE-2023-23333. As of the last NVD update on 2025-03-26, users should verify with the vendor whether a patched firmware version is available for SolarView Compact devices. Always ensure firmware updates are obtained from official Contec sources to avoid supply chain risks.

Workarounds

• Implement strict network access controls to limit who can reach the SolarView Compact web interface
• Deploy a reverse proxy with input validation and WAF capabilities in front of the device
• If possible, disable web-based management and use alternative management methods
• Monitor for and block requests containing command injection patterns at the network perimeter

# Example iptables rule to restrict access to SolarView Compact management interface
# Allow access only from trusted management network (adjust IP range as needed)
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP