CVE-2019-19100 in Automation Studio
Summary
by MITRE
A privilege escalation vulnerability in the upgrade service in B&R Automation Studio versions 4.0.x, 4.1.x, 4.2.x, < 4.3.11SP, < 4.4.9SP, < 4.5.4SP, <. 4.6.3SP, < 4.7.2 and < 4.8.1 allow authenticated users to delete arbitrary files via an exposed interface.
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Analysis
by VulDB Data Team • 06/04/2024
The privilege escalation vulnerability identified as CVE-2019-19100 affects B&R Automation Studio software versions within specific release ranges, creating a critical security gap that enables authenticated users to execute arbitrary file deletion operations through an exposed interface. This vulnerability resides within the upgrade service component of the automation software, which is designed to facilitate system updates and maintenance activities. The flaw represents a significant deviation from expected security boundaries, as it allows users who have already authenticated to the system to perform operations that should typically be restricted to administrative or system-level privileges. The affected versions span multiple minor releases across the 4.0.x through 4.7.x series, indicating this weakness has persisted across several iterations of the software.
The technical implementation of this vulnerability stems from insufficient input validation and access control mechanisms within the upgrade service interface. When authenticated users interact with the exposed interface, the system fails to properly validate file paths or enforce proper authorization checks before executing deletion operations. This creates a directory traversal or path manipulation scenario where maliciously crafted file references can target system files beyond the intended scope of normal operation. The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and CWE-73, which covers external control of file name or path. The flaw essentially allows an authenticated user to bypass normal file system access controls and delete files that they would not normally have permission to modify or remove, creating a potential pathway for system disruption or further attack vectors.
The operational impact of this vulnerability extends beyond simple file deletion capabilities, as it fundamentally compromises the integrity and availability of the automation environment. An attacker who has gained access to the system through legitimate authentication can leverage this privilege escalation to remove critical system files, configuration data, or even executable components that maintain the software's functionality. This capability can lead to complete system outages, data loss, or provide a foothold for additional attacks within the network infrastructure. The vulnerability affects industrial automation environments where B&R Automation Studio is deployed, potentially impacting critical manufacturing processes, control systems, or operational technology environments. The exposure of the upgrade service interface to authenticated users creates a persistent risk that can be exploited by both internal malicious actors and external threat groups targeting industrial control systems. This vulnerability directly impacts the principle of least privilege and can be classified under ATT&CK technique T1059.001 for command and scripting interpreter, as it enables execution of unauthorized file operations through legitimate system interfaces.
Mitigation strategies for CVE-2019-19100 should prioritize immediate patch application to the affected software versions, with administrators upgrading to the patched releases that address the access control and input validation deficiencies. Organizations should implement network segmentation to restrict access to the upgrade service interface, ensuring that only authorized administrative personnel can reach the exposed endpoints. Additional controls include disabling unnecessary upgrade service components when not actively required for system maintenance, implementing strict firewall rules to limit access to the specific ports used by the upgrade service, and conducting regular security audits of the automation environment. System administrators should also establish monitoring for unauthorized file deletion activities and implement robust logging mechanisms to track access to the upgrade service interface. The vulnerability highlights the importance of secure coding practices and proper input validation in industrial software development, particularly when dealing with system maintenance functions that require elevated privileges. Organizations should review their access control policies and ensure that only necessary personnel have authentication credentials for systems containing vulnerable software components. The remediation process should include comprehensive testing of patched versions to ensure that legitimate upgrade functionality remains intact while the privilege escalation vulnerability is properly addressed.