CVE-2025-11787: Circutor SGE-PLC1000 Firmware RCE Flaw

CVE-2025-11787 Overview

CVE-2025-11787 is a command injection vulnerability affecting Circutor SGE-PLC1000 and SGE-PLC50 industrial devices running firmware version 9.0.2. The flaw resides in the operating system layer and is reachable through the GetDNS(), CheckPing(), and TraceRoute() functions exposed by the device. An authenticated attacker with low privileges can inject arbitrary operating system commands through these network diagnostic functions. The vulnerability is tracked under CWE-78 (Improper Neutralization of Special Elements used in an OS Command).

Critical Impact
Successful exploitation allows arbitrary command execution on the underlying operating system of the Circutor SGE-PLC1000 and SGE-PLC50, compromising confidentiality, integrity, and availability of these industrial control devices.

Affected Products

Circutor SGE-PLC1000 firmware version 9.0.2
Circutor SGE-PLC50 firmware version 9.0.2
Associated SGE-PLC1000 and SGE-PLC50 hardware platforms

Discovery Timeline

2025-12-02 - CVE-2025-11787 published to NVD
2025-12-03 - Last updated in NVD database

Technical Details for CVE-2025-11787

Vulnerability Analysis

The Circutor SGE-PLC1000 and SGE-PLC50 expose network diagnostic functionality through three application functions: GetDNS(), CheckPing(), and TraceRoute(). These functions accept user-supplied parameters such as hostnames or IP addresses and pass them to underlying operating system utilities. The application fails to neutralize shell metacharacters before constructing the command string. An attacker who supplies crafted input containing characters such as ;, |, &, or backticks can append additional commands that execute in the context of the device's operating system process.

Because the vulnerable functions are part of the device management interface, the attack surface is reachable over the network. The CVSS 4.0 vector indicates the attacker requires low privileges and user interaction, but successfully executing commands yields high impact on confidentiality, integrity, and availability. The EPSS score is 0.186% at the 40.083 percentile.

Root Cause

The root cause is improper neutralization of special elements in OS command construction [CWE-78]. The GetDNS(), CheckPing(), and TraceRoute() handlers concatenate user-controlled input directly into shell command strings without input validation, parameterization, or escaping of shell metacharacters.

Attack Vector

The attack vector is network-based. An authenticated attacker submits a malicious payload to the diagnostic endpoints invoking GetDNS(), CheckPing(), or TraceRoute(). The payload embeds shell metacharacters followed by attacker-chosen commands. The injected commands execute with the privileges of the service handling the diagnostic request. This typically grants control over device configuration, network traffic, and any connected industrial process the PLC participates in.

No verified public exploit code is available. The vulnerability mechanism is described by the INCIBE Security Notice on Vulnerabilities.

Detection Methods for CVE-2025-11787

Indicators of Compromise

Unexpected child processes spawned by the device web management service following requests to diagnostic endpoints invoking GetDNS(), CheckPing(), or TraceRoute().
HTTP request bodies or query parameters containing shell metacharacters such as ;, |, &&, `, or $() in fields expected to hold hostnames or IP addresses.
Outbound connections from the PLC to unfamiliar destinations following diagnostic function calls.
New or modified files on the device filesystem outside of scheduled firmware update windows.

Detection Strategies

Inspect network traffic to Circutor SGE-PLC1000 and SGE-PLC50 management interfaces for requests targeting diagnostic functions containing non-alphanumeric payloads.
Correlate authentication events with subsequent diagnostic function invocations to identify low-privilege accounts performing unusual command execution patterns.
Apply signatures for OS command injection patterns at network intrusion identification sensors monitoring the OT network segment.

Monitoring Recommendations

Forward management interface logs from Circutor devices to a centralized logging platform and alert on diagnostic function calls outside of approved maintenance windows.
Baseline normal PLC outbound network behavior and alert on deviations that may indicate command-and-control traffic from a compromised device.
Monitor account usage on the PLC, particularly low-privilege accounts capable of invoking the affected diagnostic functions.

How to Mitigate CVE-2025-11787

Immediate Actions Required

Restrict network access to Circutor SGE-PLC1000 and SGE-PLC50 management interfaces to a dedicated administrative VLAN or jump host.
Rotate credentials for all accounts on affected devices and remove unused accounts that could be leveraged to reach the vulnerable functions.
Disable or block external access to the GetDNS(), CheckPing(), and TraceRoute() diagnostic endpoints if the device permits this configuration.
Consult the INCIBE Security Notice on Vulnerabilities for vendor-coordinated guidance.

Patch Information

At the time of publication, no vendor patch URL is listed in the CVE record. Affected firmware is Circutor SGE-PLC1000 and SGE-PLC50 version 9.0.2. Operators should contact Circutor directly to obtain remediation guidance and any firmware updates addressing CVE-2025-11787, and monitor the INCIBE-CERT advisory for updates.

Workarounds

Place affected devices behind a firewall that permits management traffic only from explicitly trusted engineering workstations.
Enforce network segmentation between the OT network hosting the PLCs and corporate or internet-facing networks to reduce reachability.
Apply application-layer filtering on management traffic to strip or reject shell metacharacters in hostname and IP address parameters.
Audit and minimize the number of accounts with permission to invoke diagnostic functions on affected devices.

bash

# Example firewall rule restricting management access to a trusted host
iptables -A INPUT -p tcp --dport 443 -s 10.10.5.20 -d 10.20.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -d 10.20.0.0/24 -j DROP