CVE-2023-0776: Baicells Neutrino 430 Firmware RCE Flaw

CVE-2023-0776 Overview

CVE-2023-0776 is a pre-authentication command injection vulnerability affecting Baicells LTE TDD eNodeB devices, including the Nova 436Q, Nova 430E, Nova 430I, and Neutrino 430 models running firmware through QRTB 2.12.7. Attackers can inject operating system commands through HTTP requests without authentication. The injected commands execute with root privileges on the affected devices. The flaw maps to [CWE-77] Command Injection and [CWE-79]. Successful exploitation gives an unauthenticated network attacker full control over the radio access network equipment, with potential to pivot into connected mobile network infrastructure.

Critical Impact
Unauthenticated remote attackers can execute arbitrary shell commands as root on exposed Baicells eNodeB devices, leading to full device compromise and potential cellular network disruption.

Affected Products

Baicells Nova 436Q LTE TDD eNodeB (firmware through QRTB 2.12.7)
Baicells Nova 430E and Nova 430I LTE TDD eNodeB (firmware through QRTB 2.12.7)
Baicells Neutrino 430 LTE TDD eNodeB (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

The vulnerability resides in the HTTP management interface of the Baicells eNodeB firmware. The web server processes attacker-supplied parameters and passes them into shell command execution without sanitization. Because the affected endpoints are reachable before any login or session establishment, no credentials are required to trigger the flaw. The web server process runs as root, so injected commands inherit full privileges.

A third-party analyst validated exploitation steps, with Rustam Amin credited in the NVD entry for providing reproduction details. The vulnerability is classified under [CWE-77] Improper Neutralization of Special Elements used in a Command and [CWE-79]. Successful exploitation allows an attacker to read configuration files, extract subscriber and operator credentials, modify radio parameters, or use the device as a foothold in the carrier network.

Root Cause

The firmware fails to validate or escape user-controlled input embedded in HTTP request parameters before invoking shell utilities. Pre-authentication HTTP handlers in the web management application pass these parameters directly to system command execution functions, allowing shell metacharacters such as semicolons, backticks, and pipes to break out of the intended command context.

Attack Vector

An attacker sends a crafted HTTP request to the management interface of an internet-exposed or LAN-accessible Baicells eNodeB. The request targets a pre-authentication endpoint that constructs an operating system command using request parameters. The injected payload executes immediately as root. No user interaction or prior credentials are required. Technical reproduction details are referenced in the Baicells Firmware Service advisory.

Detection Methods for CVE-2023-0776

Indicators of Compromise

Unexpected outbound connections from eNodeB management interfaces to unknown external hosts.
HTTP requests to the device web interface containing shell metacharacters such as ;, |, `, $(, or URL-encoded equivalents.
New or modified files in writable firmware directories, particularly cron entries, startup scripts, or /tmp payload binaries.
Unauthorized configuration changes affecting radio parameters, SNMP communities, or remote management endpoints.

Detection Strategies

Inspect HTTP traffic to and from eNodeB management IPs for command injection patterns in query strings and POST bodies.
Correlate authentication logs with command execution events to identify activity occurring without a valid session.
Hash firmware components and compare against vendor-supplied baselines to detect tampering.

Monitoring Recommendations

Forward eNodeB syslog, HTTP access logs, and management plane netflow into a centralized analytics platform for longitudinal review.
Alert on any HTTP request to the eNodeB management interface originating from outside the operations subnet.
Track process creation events on devices that support remote logging, focusing on shells spawned by the web server process.

How to Mitigate CVE-2023-0776

Immediate Actions Required

Remove eNodeB management interfaces from the public internet and restrict access to a dedicated operations VLAN.
Place affected devices behind a firewall or jump host that enforces source IP allowlisting for HTTP and HTTPS management.
Audit all Baicells eNodeB devices in inventory and identify any running firmware at or below QRTB 2.12.7.
Rotate any credentials, SNMP communities, or API tokens that were stored on potentially exposed devices.

Patch Information

Baicells publishes updated firmware images through its support portal. Operators should obtain and deploy the latest firmware release for each affected model from the Baicells Firmware Service. Validate firmware integrity using vendor-provided checksums before installation, and reboot devices to complete the update.

Workarounds

Block inbound TCP traffic to the eNodeB HTTP and HTTPS management ports from any untrusted network segment.
Terminate management access through a VPN concentrator that enforces multi-factor authentication before any traffic reaches the device.
Disable remote web management on devices where local or out-of-band administration is sufficient until firmware can be updated.

bash

# Example ACL restricting eNodeB management access to an operations subnet
iptables -A INPUT -p tcp -s 10.10.50.0/24 --dport 80 -j ACCEPT
iptables -A INPUT -p tcp -s 10.10.50.0/24 --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP