---
title: "Critical Vulnerability in Contemporary Controls BASC 20T: Risks and Mitigations"
short_title: "Critical flaw in Contemporary Controls BASC 20T"
description: "A severe vulnerability (CVE-2025-13926) in Contemporary Controls BASC 20T exposes systems to remote attacks. Learn risks, impacts, and mitigation steps now."
author: "Vitus"
date: 2025-01-24
categories: [Cybersecurity, Vulnerabilities]
tags: [cve-2025-13926, plc security, ics vulnerabilities, critical infrastructure, cybersecurity]
score: 0.85
cve_ids: [CVE-2025-13926]
---
TL;DR
A critical vulnerability (CVE-2025-13926) in the Contemporary Controls BASC 20T programmable logic controller (PLC) allows attackers to enumerate functionality, reconfigure systems, and execute remote procedure calls. With a CVSS score of 9.8, this flaw poses severe risks to critical infrastructure sectors like energy, manufacturing, and commercial facilities. Users are urged to contact Contemporary Controls for mitigation guidance, as the product is obsolete.
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Main Content
Introduction
Industrial control systems (ICS) are the backbone of critical infrastructure, managing everything from energy grids to manufacturing plants. However, their increasing connectivity also exposes them to cyber threats. A recently disclosed vulnerability in the Contemporary Controls BASC 20T, a widely deployed PLC, highlights the urgent need for robust security measures. CVE-2025-13926 enables attackers to exploit untrusted inputs, potentially leading to unauthorized access, system reconfiguration, and data breaches.
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Key Points
- Critical Vulnerability: CVE-2025-13926 has a CVSS score of 9.8, categorizing it as critical.
- Affected Systems: The flaw impacts Contemporary Controls BASC 20T (version 3.1), an obsolete PLC still in use across critical infrastructure sectors.
- Exploitation Risks: Attackers can enumerate functionality, reconfigure systems, delete files, and execute remote procedure calls by forging packets from sniffed network traffic.
- Global Impact: Deployed worldwide, the vulnerable device is used in energy, manufacturing, and commercial facilities.
- Mitigation: Contemporary Controls recommends users contact their support team for guidance, as no direct patch is available.
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Technical Details
#### Vulnerability Overview
CVE-2025-13926 stems from a reliance on untrusted inputs in security decisions (CWE-807). Attackers can exploit this flaw by:
1. Sniffing network traffic to gather data about the target system.
2. Forging packets to send arbitrary requests to the BASC 20T PLC.
3. Executing malicious actions, such as reconfiguring the device, transferring files, or making remote procedure calls.
#### CVSS Metrics
The vulnerability has been assigned the following CVSS metrics:
- Base Score: 9.8 (Critical)
- Vector String: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- Impact: High confidentiality, integrity, and availability impacts.
#### Affected Products
- Vendor: Contemporary Controls Sedona Alliance
- Product: BASControl20 (Version 3.1)
- Status: Known to be affected
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Impact Assessment
#### Sectors at Risk
The vulnerability poses significant threats to the following critical infrastructure sectors:
- Energy: Power generation and distribution systems.
- Critical Manufacturing: Industrial automation and control systems.
- Commercial Facilities: Building management and HVAC systems.
#### Potential Consequences
Successful exploitation could lead to:
- Unauthorized system access and control.
- Disruption of operations, causing downtime and financial losses.
- Data breaches or manipulation of sensitive information.
- Physical safety risks if attackers gain control of industrial processes.
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Mitigation Steps
Contemporary Controls has classified the BASC 20T as obsolete and recommends the following actions:
1. Contact Support: Users should reach out to Contemporary Controls for guidance on mitigating the vulnerability.
- [Contact Technical Support](https://www.ccontrols.com/support/contacttech.htm)
2. Network Segmentation: Isolate control system networks from business networks using firewalls.
3. Minimize Exposure: Ensure control system devices are not accessible from the internet.
4. Secure Remote Access: Use virtual private networks (VPNs) for remote access, ensuring they are updated to the latest version.
5. Monitor for Malicious Activity: Implement intrusion detection systems to identify and respond to suspicious behavior.
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Attack Vector
Attackers can exploit CVE-2025-13926 by:
- Sniffing network traffic to capture data packets.
- Analyzing captured data to understand system functionality.
- Forging malicious packets to send unauthorized requests to the PLC.
- Executing arbitrary commands, such as reconfiguring the device or transferring files.
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Affected Systems
| Vendor | Product | Version | Vulnerability |
|--------------------------|---------------------------------|---------------------------|--------------------------------------------|
| Contemporary Controls | BASControl20 | 3.1 | Reliance on Untrusted Inputs in Security Decisions |
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Conclusion
The discovery of CVE-2025-13926 underscores the growing cybersecurity risks facing industrial control systems. With a CVSS score of 9.8, this vulnerability demands immediate attention from organizations using the Contemporary Controls BASC 20T. While the product is obsolete, users must take proactive steps to mitigate risks, such as isolating networks and contacting the vendor for support.
As cyber threats to critical infrastructure evolve, organizations must prioritize defensive strategies, including regular security assessments, network segmentation, and employee training. Failure to address such vulnerabilities could result in severe operational disruptions, financial losses, and compromised safety.
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References
[^1]: CISA. "[ICSA-26-099-01: Contemporary Controls BASC 20T Vulnerability](https://www.cisa.gov/news-events/ics-advisories/icsa-26-099-01)". Retrieved 2025-01-24.
[^2]: MITRE. "[CWE-807: Reliance on Untrusted Inputs in a Security Decision](https://cwe.mitre.org/data/definitions/807.html)". Retrieved 2025-01-24.
[^3]: NIST. "[CVE-2025-13926 Detail](https://www.cve.org/CVERecord?id=CVE-2025-13926)". Retrieved 2025-01-24.