Overview
CVE-2025-41738 is a high-severity vulnerability affecting the visualization server of the CODESYS Control runtime system. This vulnerability allows an unauthenticated remote attacker to trigger a denial-of-service (DoS) condition. The issue stems from the visualization server accessing a resource with a pointer of an incorrect type, leading to potential crashes or instability within the CODESYS environment.
This vulnerability was published on 2025-12-01T10:16:01.130.
Technical Details
The vulnerability exists due to improper handling of data types within the visualization server. Specifically, the server attempts to access a resource using a pointer that does not match the resource’s actual data type. This can happen during the processing of network requests related to visualization data. The incorrect pointer dereference can lead to memory corruption, program crashes, and ultimately, a denial-of-service condition for the CODESYS Control runtime system. No authentication is required to exploit this vulnerability, making it particularly dangerous.
CVSS Analysis
The Common Vulnerability Scoring System (CVSS) score for CVE-2025-41738 is 7.5 (HIGH).
This score reflects the following characteristics:
- Attack Vector (AV): Network (N) – The vulnerability can be exploited over a network.
- Attack Complexity (AC): Low (L) – Exploitation requires minimal effort.
- Privileges Required (PR): None (N) – No privileges are required to exploit the vulnerability.
- User Interaction (UI): None (N) – No user interaction is required.
- Scope (S): Unchanged (U) – An exploited vulnerability can only affect resources managed by the same security authority.
- Confidentiality Impact (C): None (N) – There is no impact to confidentiality.
- Integrity Impact (I): None (N) – There is no impact to integrity.
- Availability Impact (A): High (H) – The vulnerability can cause a denial-of-service.
Possible Impact
A successful exploit of CVE-2025-41738 can lead to the following:
- Denial-of-Service (DoS): The CODESYS Control runtime system becomes unavailable, potentially halting critical industrial processes controlled by the system.
- Operational Disruption: The affected industrial processes may be interrupted, leading to production losses and potential safety hazards.
- System Instability: Repeated exploitation attempts can cause long-term instability of the CODESYS environment.
Mitigation or Patch Steps
The primary mitigation strategy is to apply the patch or update provided by CODESYS. Check the CODESYS website for updates and security advisories. In addition, consider the following steps:
- Apply the Patch: Immediately apply the patch or update provided by CODESYS to address the vulnerability.
- Network Segmentation: Implement network segmentation to isolate the CODESYS Control runtime system from untrusted networks.
- Access Control: Restrict access to the CODESYS Control runtime system to authorized personnel only.
- Intrusion Detection: Implement intrusion detection systems (IDS) to monitor network traffic for suspicious activity.
- Firewall Rules: Configure firewalls to block unauthorized access to the CODESYS Control runtime system.
- Regular Backups: Maintain regular backups of the CODESYS Control runtime system to facilitate recovery in case of a successful attack.
