CVE-2026-44402: Voltronic Power SNMP Web Pro RCE Vulnerability

CVE-2026-44402 Overview

CVE-2026-44402 is an unauthenticated remote code execution vulnerability in Voltronic Power SNMP Web Pro 1.1. The flaw resides in the upload.cgi firmware update endpoint, which accepts crafted tar archives without validating the requester's credentials. Attackers can upload arbitrary executable files that are extracted into a privileged directory and executed as root. Successful exploitation results in full system compromise of the affected UPS management interface. The vulnerability is classified as an unrestricted file upload weakness under [CWE-434].

Critical Impact
Unauthenticated network attackers can achieve root-level code execution by submitting a malicious tar archive to upload.cgi, requiring no credentials or user interaction.

Affected Products

Voltronic Power SNMP Web Pro 1.1
upload.cgi firmware update endpoint
UPS devices managed through the SNMP Web Pro web interface

Discovery Timeline

2026-09-04 - CVE-2026-44402 published to the National Vulnerability Database
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-44402

Vulnerability Analysis

The vulnerability affects the firmware update workflow exposed through the upload.cgi endpoint of the SNMP Web Pro web interface. The endpoint accepts tar archives intended to deliver legitimate firmware images. However, the handler neither authenticates the request nor validates the contents of the archive before extraction. An attacker can package arbitrary binaries or scripts inside a tar archive and submit them over the network. The web application extracts the archive into a privileged filesystem location and then executes files from that location with root privileges. The result is unauthenticated remote code execution against the device operating system.

Root Cause

The root cause is an unrestricted file upload flaw combined with missing authentication on a privileged administrative endpoint. The firmware update handler trusts the archive contents and performs extraction and execution as root without verifying file types, signatures, or the identity of the uploader.

Attack Vector

The attack vector is the network. An attacker with reachability to the device's HTTP interface issues a POST request to upload.cgi carrying a crafted tar archive. No credentials, tokens, or user interaction are required. Detailed exploitation mechanics are documented in the Vulncheck advisory on Voltronic RCE and the public proof-of-concept repository.

// No verified exploit code is reproduced here.
// See the Vulncheck advisory and public PoC repository referenced above
// for exploitation details.

Detection Methods for CVE-2026-44402

Indicators of Compromise

Unexpected HTTP POST requests to the upload.cgi endpoint from external or unauthorized source addresses.
New or modified executable files in the firmware update extraction directory used by the SNMP Web Pro service.
Unexplained child processes spawned by the web server process running as root on the UPS management device.
Outbound network connections initiated by the UPS device to unfamiliar hosts following an upload event.

Detection Strategies

Inspect web server access logs for POST requests to upload.cgi that lack an authenticated session context.
Monitor the SNMP Web Pro filesystem for tar archive extraction events outside of scheduled firmware update windows.
Alert on process creation events where the web service parent spawns shell interpreters or unknown binaries.

Monitoring Recommendations

Capture and retain full HTTP request bodies to upload.cgi for forensic review when the device supports it.
Baseline normal firmware update cadence and flag out-of-band update attempts for investigation.
Forward device logs and network flow telemetry to a centralized analytics platform for correlation across the fleet.

How to Mitigate CVE-2026-44402

Immediate Actions Required

Remove SNMP Web Pro management interfaces from any network segment reachable by untrusted users, including the public internet.
Restrict access to upload.cgi at the network layer using firewall rules or access control lists that permit only administrative source addresses.
Audit affected devices for signs of prior exploitation, including unauthorized binaries in firmware directories and unexpected root processes.
Rotate credentials and keys stored on or accessible from compromised UPS management interfaces.

Patch Information

No vendor patch is referenced in the available CVE data. Consult the Voltronic Power homepage and the Vulncheck advisory for updated remediation guidance and firmware availability.

Workarounds

Place the SNMP Web Pro device behind a VPN or management jump host that enforces authentication before HTTP access.
Disable the web management interface when it is not actively required for administration.
Segment UPS management devices onto an isolated operational technology VLAN with strict egress filtering.

bash

# Example: restrict access to the SNMP Web Pro web interface to an admin subnet
# Replace 10.10.10.0/24 with your authorized management network
iptables -A INPUT -p tcp --dport 80 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP