CISA Alerts on Critical OpenPLC ScadaBR Vulnerability Exploited in Attacks
The Cybersecurity and Infrastructure Security Agency (CISA) has recently added a critical vulnerability in OpenPLC ScadaBR to its Known Exploited Vulnerabilities (KEV) catalog, signaling active exploitation in the wild. This flaw, identified as CVE-2021-26828, poses significant risks to industrial control systems by allowing remote authenticated users to upload and execute arbitrary JSP files through the `view_edit.shtm` interface.
Understanding the Vulnerability
OpenPLC ScadaBR is a web-based platform widely utilized in industrial automation for monitoring and controlling processes. The identified vulnerability is classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. This security weakness enables authenticated attackers to bypass existing security controls, injecting malicious code directly into vulnerable systems.
The exploitation of this flaw allows attackers to upload and execute JSP files, granting them persistent access and the capability to execute arbitrary code within the industrial environment. Such unauthorized access can disrupt critical operations and facilitate lateral movement within industrial networks, potentially leading to severe operational and financial consequences.
Technical Details
– CVE ID: CVE-2021-26828
– Vulnerability Type: Unrestricted Upload of File with Dangerous Type
– Affected Product: OpenPLC ScadaBR
– Attack Vector: Network-based, Remote
– CVSS Severity: Critical
– Impact: Remote Code Execution (RCE) via JSP file upload
Implications for Industrial Control Systems
The ability to upload and execute arbitrary JSP files within OpenPLC ScadaBR systems presents a direct threat to industrial control environments. Attackers can exploit this vulnerability to gain unauthorized access, manipulate system configurations, and disrupt essential industrial processes. The potential for such disruptions underscores the critical need for immediate remediation to maintain operational integrity and security.
CISA’s Recommendations and Remediation Timeline
CISA has set a remediation deadline of December 24, 2025, for organizations to address this vulnerability. Federal agencies and critical infrastructure operators are urged to prioritize the following actions:
1. Apply Vendor-Supplied Mitigations: Implement patches or configuration changes provided by the manufacturer to address the vulnerability.
2. Follow Cloud Deployment Guidance: For cloud-based deployments, adhere to the guidelines outlined in Binding Operational Directive (BOD 22-01) to ensure compliance and security.
3. Discontinue Use if Necessary: If adequate mitigations are unavailable or cannot be applied, consider discontinuing the use of OpenPLC ScadaBR to prevent potential exploitation.
While there is no confirmed evidence linking this vulnerability to active ransomware campaigns, its nature makes it an attractive target for threat actors focusing on industrial control systems. The ability to upload and execute malicious files within such environments provides a direct pathway to system compromise, especially in settings where security monitoring may be limited.
Immediate Actions for Organizations
Organizations utilizing OpenPLC ScadaBR should take the following steps to mitigate the risk associated with CVE-2021-26828:
– Inventory Affected Systems: Identify all instances of OpenPLC ScadaBR within the organization to assess exposure.
– Validate Patch Status: Ensure that all identified systems are updated with the latest patches addressing the vulnerability.
– Implement Network Segmentation: Limit access to administrative interfaces by segmenting networks to reduce the attack surface.
– Restrict File Uploads: Utilize firewall rules and other security measures to control and monitor file upload activities.
– Enhance Monitoring: Increase vigilance for suspicious JSP file uploads and review access logs for any signs of exploitation.
– Coordinate with Vendors: Engage with industrial automation vendors to confirm the availability and deployment procedures for necessary patches.
Conclusion
The inclusion of CVE-2021-26828 in CISA’s KEV catalog highlights the ongoing risks associated with vulnerabilities in industrial control systems. Organizations must remain proactive in their cybersecurity efforts, ensuring timely patch management and adherence to best practices to safeguard critical infrastructure. By addressing this vulnerability promptly, organizations can mitigate potential threats and maintain the security and reliability of their industrial operations.
