CVE-2023-0776: Baicells Neutrino 430 RCE Vulnerability

CVE-2023-0776 Overview

CVE-2023-0776 is a critical command injection vulnerability affecting multiple Baicells LTE TDD eNodeB devices, including the Nova 436Q, Nova 430E, Nova 430I, and Neutrino 430 models. Devices running firmware through QRTB 2.12.7 are vulnerable to remote shell code exploitation via HTTP command injections. Critically, these commands are executed using pre-login execution paths, meaning no authentication is required, and the injected commands run with root permissions on the affected devices.

Critical Impact

Unauthenticated remote attackers can execute arbitrary shell commands with root privileges on affected Baicells eNodeB devices, potentially compromising telecommunications infrastructure and enabling complete device takeover.

Affected Products

• Baicells Nova 436Q with firmware through QRTB 2.12.7
• Baicells Nova 430E with firmware through QRTB 2.12.7
• Baicells Nova 430I/Nova 430L with firmware through QRTB 2.12.7
• Baicells Neutrino 430 with firmware through QRTB 2.12.7

Discovery Timeline

• 2023-02-11 - CVE-2023-0776 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-0776

Vulnerability Analysis

This vulnerability represents a severe security flaw in the HTTP interface of Baicells LTE eNodeB devices. The affected firmware fails to properly sanitize user-supplied input in HTTP requests before passing it to system shell commands. Because the vulnerability exists in pre-authentication code paths, attackers do not need any credentials to exploit it. Furthermore, the web service runs with elevated privileges, causing all injected commands to execute as root.

The vulnerability is classified under CWE-77 (Command Injection) and CWE-79 (Cross-Site Scripting), indicating that the HTTP interface suffers from multiple input validation failures. The command injection aspect is particularly dangerous as it allows direct interaction with the underlying operating system.

Root Cause

The root cause of CVE-2023-0776 lies in inadequate input validation and sanitization within the HTTP request handling code of the Baicells firmware. User-controllable data from HTTP requests is concatenated directly into shell command strings without proper escaping or validation. This allows attackers to break out of the intended command context and inject arbitrary shell commands. The combination of pre-authentication accessibility and root-level execution privileges significantly amplifies the severity of this vulnerability.

Attack Vector

The attack vector is network-based, requiring only HTTP access to the vulnerable device's management interface. An attacker can exploit this vulnerability by crafting malicious HTTP requests containing shell metacharacters and commands within parameters that are processed by the vulnerable firmware.

The attack flow typically involves:

1. Identifying an exposed Baicells eNodeB device with firmware version QRTB 2.12.7 or earlier
2. Sending specially crafted HTTP requests to the device's management interface
3. Including command injection payloads in vulnerable parameters
4. Achieving remote command execution with root privileges without any authentication

The vulnerability has been validated by third-party security researcher Rustam Amin, who provided reproducible exploitation steps. Given the nature of eNodeB devices in telecommunications infrastructure, successful exploitation could allow attackers to intercept communications, disrupt cellular service, or use the compromised device as a pivot point for further attacks.

Detection Methods for CVE-2023-0776

Indicators of Compromise

• Unexpected outbound network connections from eNodeB devices to unknown IP addresses
• Unusual processes or services running on the device that are not part of standard firmware
• Anomalous HTTP requests to the device management interface containing shell metacharacters (;, |, $(), backticks)
• Modified configuration files or unauthorized firmware changes on affected devices

Detection Strategies

• Monitor HTTP access logs for requests containing command injection patterns such as semicolons, pipes, or command substitution syntax
• Implement network-based intrusion detection rules to identify exploitation attempts targeting the management interface
• Deploy SentinelOne Singularity platform to detect post-exploitation activities and lateral movement from compromised network infrastructure devices
• Conduct regular firmware version audits to identify devices running vulnerable versions through QRTB 2.12.7

Monitoring Recommendations

• Segment eNodeB device management interfaces from general network traffic using VLANs or firewall rules
• Enable comprehensive logging on network firewalls protecting access to device management interfaces
• Implement alerting for any authentication failures or unusual access patterns to telecommunications infrastructure

How to Mitigate CVE-2023-0776

Immediate Actions Required

• Identify all Baicells Nova 436Q, Nova 430E, Nova 430I/L, and Neutrino 430 devices in your environment and verify their firmware versions
• Restrict network access to device management interfaces using firewall rules or access control lists
• Place management interfaces behind a VPN or jump host to prevent direct internet exposure
• Monitor affected devices for signs of compromise until patches can be applied

Patch Information

Baicells has been notified of this vulnerability and users should check the Baicells Firmware Service for updated firmware versions that address CVE-2023-0776. Organizations should apply firmware updates as soon as they become available and verify the installation completes successfully.

Workarounds

• Implement strict network segmentation to isolate eNodeB device management interfaces from untrusted networks
• Deploy a web application firewall (WAF) in front of the management interface to filter malicious HTTP requests containing command injection patterns
• Disable remote management access entirely if not operationally required, limiting access to local console connections only
• Use VPN or SSH tunneling for all remote management access to create an authenticated access layer

# Example firewall rule to restrict management interface access
# Allow management access only from trusted administrative subnet
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP