Overview
The Common Vulnerabilities and Exposures system (CVE), a list of publicly disclosed cybersecurity vulnerabilities, has identified a significant flaw in the CODESYS Control runtime system. This vulnerability, identified as CVE-2025-41659, could allow a low-privileged attacker to remotely access the Public Key Infrastructure (PKI) folder and manipulate certificates and keys, which could lead to potential system compromise or data leakage.
The flaw is particularly concerning as it affects the secure communication protocols of the Control runtime system, which is widely used in industries such as manufacturing, energy, water, and automation sectors. The vulnerability’s serious nature is underscored by its CVSS Severity Score of 8.3, indicating a high level of severity.
Vulnerability Summary
CVE ID: CVE-2025-41659
Severity: High (CVSS Score 8.3)
Attack Vector: Network
Privileges Required: Low
User Interaction: None
Impact: Potential system compromise and data leakage
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Product | Affected Versions
CODESYS Control runtime system | All versions prior to [Insert fixed version]
How the Exploit Works
This exploit takes advantage of an insecure configuration in the CODESYS Control runtime system. A low-privileged attacker can send specially crafted requests to the system, allowing them to remotely access the PKI folder. Once inside, they can read and write certificates and keys. These actions can lead to sensitive data extraction or accepting certificates as trusted. If the certificates are deleted, the system defaults to unencrypted communication.
Conceptual Example Code
The vulnerability could potentially be exploited with a simple HTTP request like the following:
GET /PKI/folder/path HTTP/1.1
Host: vulnerable.codesys.controlOnce the attacker gains access to the PKI folder, they can then manipulate the certificates and keys, for example:
PUT /PKI/folder/path/certificate HTTP/1.1
Host: vulnerable.codesys.control
Content-Type: application/x-pem-file
-----BEGIN CERTIFICATE-----
(Malicious Certificate)
-----END CERTIFICATE-----These examples are conceptual and for illustrative purposes only. The actual exploit might require more sophisticated methods or specific conditions.
Mitigation Guidance
The primary mitigation method for this vulnerability is to apply the vendor’s patch. If a patch is not yet available or cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These systems can monitor traffic and detect suspicious activities that may indicate an attempted exploitation of the vulnerability. However, these are not long-term solutions, and it’s crucial to apply the patch as soon as possible to ensure maximum security.