Published: 2025-12-02
Overview
This article provides a detailed analysis of CVE-2025-11783, a stack-based buffer overflow vulnerability affecting Circutor SGE-PLC1000 and SGE-PLC50 devices running version 9.0.2. This vulnerability, located within the AddEvent() function, could potentially allow an attacker to execute arbitrary code remotely.
Technical Details
The vulnerability resides in the AddEvent() function. The issue arises when the function copies a user-supplied username into a fixed-size buffer of 48 bytes. Critically, the code lacks proper boundary checking. If the provided username exceeds this 48-byte limit, a stack-based buffer overflow occurs. By carefully crafting a malicious username, an attacker could overwrite adjacent memory on the stack, including return addresses, to redirect program execution and ultimately achieve remote code execution.
The specific vulnerable code snippet (based on analysis of similar buffer overflows) might resemble something like this:
char username_buffer[48];
strcpy(username_buffer, user_input); // Vulnerable: no bounds check!
CVSS Analysis
Unfortunately, the Common Vulnerability Scoring System (CVSS) score and severity level are currently unavailable (N/A). A proper risk assessment requires a thorough understanding of the attack vector, exploitability, and potential impact within a specific environment. When available, the CVSS score will provide a standardized measure of the vulnerability’s severity.
Possible Impact
The exploitation of this vulnerability could have severe consequences, including:
- Remote Code Execution (RCE): An attacker could gain complete control over the affected PLC device.
- Denial of Service (DoS): Overwriting crucial system data could cause the PLC to crash or become unresponsive.
- Tampering with Industrial Processes: An attacker could manipulate the PLC’s logic to disrupt or sabotage industrial processes controlled by the device.
- Lateral Movement: A compromised PLC could be used as a foothold to gain access to other devices and systems on the network.
Mitigation and Patch Steps
Currently, the most effective mitigation steps involve:
- Immediate Patching: Circutor should release a patch addressing the buffer overflow vulnerability in the
AddEvent()function. Apply this patch as soon as it becomes available. Contact Circutor support for patch availability. - Network Segmentation: Isolate the PLC network from the corporate network and the internet to limit the potential impact of a successful attack.
- Access Control: Implement strong access controls to restrict who can access and manage the PLC devices. Use multi-factor authentication where possible.
- Intrusion Detection Systems (IDS): Deploy an IDS that can detect and alert on suspicious activity related to PLC devices.
- Input Validation: Implement robust input validation on all user-supplied data to prevent buffer overflows and other input-related attacks. Although a patch is needed, defense in depth is essential.
- Disable Unnecessary Services: Disable any unnecessary services or features on the PLC to reduce the attack surface.
- Monitoring: Continuously monitor the PLC’s activity for any signs of compromise.
