CVE-2026-0936 Overview
An Insertion of Sensitive Information into Log File vulnerability (CWE-532) has been identified in B&R PVI client versions prior to 6.5. This vulnerability may be abused by an authenticated local attacker to gather credential information which is processed by the PVI client application. While the logging function of the PVI client application is disabled by default and must be explicitly enabled by the user, organizations that have enabled verbose logging for troubleshooting purposes may be at risk of credential exposure.
Critical Impact
Authenticated local attackers can extract credential information from log files when logging is enabled, potentially leading to further system compromise or lateral movement within industrial control environments.
Affected Products
- B&R PVI Client versions prior to 6.5
- Industrial automation systems utilizing B&R PVI client for process visualization
- B&R Automation Studio environments with PVI client integration
Discovery Timeline
- 2026-01-29 - CVE CVE-2026-0936 published to NVD
- 2026-01-29 - Last updated in NVD database
Technical Details for CVE-2026-0936
Vulnerability Analysis
This vulnerability falls under the Information Disclosure category, specifically involving the improper handling of sensitive credential information within application logs. The B&R PVI (Programmable Variable Interface) client is commonly used in industrial automation environments for communication between visualization applications and programmable logic controllers (PLCs).
When verbose logging is enabled, the PVI client application writes sensitive credential data to log files without proper sanitization or redaction. This creates an opportunity for authenticated local users with read access to the log directory to harvest credentials that may grant access to industrial control systems or other networked resources.
The vulnerability requires local access and authentication, meaning an attacker would need an existing foothold on the target system. Additionally, since logging is disabled by default, exploitation requires that an administrator or user has explicitly enabled the logging functionality—typically done during troubleshooting or development scenarios.
Root Cause
The root cause of this vulnerability is insufficient sanitization of sensitive data before writing to log files. The PVI client application fails to properly redact or mask credential information when logging is enabled, resulting in plaintext or easily recoverable credential data being written to persistent storage. This represents a violation of secure coding practices for handling authentication data.
Attack Vector
The attack vector is local, requiring the attacker to have authenticated access to the system running the vulnerable PVI client software. The exploitation path involves:
- Gaining authenticated local access to a system running B&R PVI client prior to version 6.5
- Identifying that verbose logging has been enabled on the target system
- Locating the PVI client log files on the local file system
- Extracting credential information from the log entries
- Using harvested credentials for further access to industrial control systems or network resources
The attacker would need to have user-level privileges on the local system to read the log files. No user interaction is required beyond the initial enabling of the logging feature by an administrator.
Detection Methods for CVE-2026-0936
Indicators of Compromise
- Unexpected access to PVI client log file directories by non-administrative users
- Anomalous file read operations targeting PVI client log files
- Credential reuse attacks originating from systems running vulnerable PVI client versions
- Suspicious local user activity on systems with PVI client installed
Detection Strategies
- Monitor file access events for PVI client log directories and flag unusual read patterns
- Implement file integrity monitoring on log directories to detect unauthorized access
- Audit local user account activity on systems running B&R PVI client software
- Review authentication logs for credential usage patterns that may indicate harvested credentials
Monitoring Recommendations
- Enable detailed auditing of file system access on systems running PVI client versions prior to 6.5
- Implement security information and event management (SIEM) rules to alert on log file access anomalies
- Regularly review which systems have PVI client logging enabled and consider disabling when not actively troubleshooting
- Monitor for lateral movement attempts from systems running vulnerable PVI client software
How to Mitigate CVE-2026-0936
Immediate Actions Required
- Upgrade B&R PVI client to version 6.5 or later on all affected systems
- Disable verbose logging on PVI client installations where it is not actively required
- Review and rotate any credentials that may have been processed by the PVI client while logging was enabled
- Restrict file system permissions on PVI client log directories to administrators only
- Audit access to systems running vulnerable versions to identify potential credential exposure
Patch Information
B&R Automation has addressed this vulnerability in PVI client version 6.5 and later. Organizations should consult the B&R Automation Security Advisory for detailed upgrade instructions and additional security guidance. It is recommended to apply the update through your organization's standard change management process, prioritizing systems in production industrial control environments.
Workarounds
- Disable the PVI client logging feature by removing or commenting out logging configuration settings if immediate patching is not possible
- Implement strict access controls on log file directories, limiting read access to essential administrative accounts only
- Consider implementing log rotation with secure deletion to minimize the exposure window for sensitive data
- Monitor log files for sensitive content and implement automated sanitization where feasible
- Isolate systems running vulnerable PVI client versions from broader network access where practical
# Example: Restrict log directory permissions (adjust path as needed)
# Windows PowerShell - Restrict PVI log directory to administrators
icacls "C:\ProgramData\BR\PVI\Logs" /inheritance:r /grant:r Administrators:F /remove Users
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
