CVE-2022-29862 in OPC UA .NET Standard
Summary
by MITRE • 06/16/2022
An infinite loop in OPC UA .NET Standard Stack 1.04.368 allows a remote attackers to cause the application to hang via a crafted message.
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Analysis
by VulDB Data Team • 06/16/2022
The vulnerability identified as CVE-2022-29862 represents a critical security flaw within the OPC UA .NET Standard Stack version 1.04.368 that exposes systems to remote denial of service attacks. This issue manifests as an infinite loop condition that occurs when the system processes a specially crafted message, leading to complete application hang and operational disruption. The vulnerability specifically affects industrial control systems and automation environments that rely on OPC UA protocol implementations for communication between devices and supervisory systems. Organizations utilizing this stack in critical infrastructure settings face significant operational risks as the flaw can be exploited remotely without requiring authentication or elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation and error handling within the OPC UA message processing routines. When the stack receives a malformed or crafted message that triggers a specific code path, the processing logic enters an infinite loop where the application continuously executes the same sequence of operations without proper termination conditions. This flaw resides in the protocol handling layer of the OPC UA .NET Standard Stack, specifically within the message parsing and validation components that are responsible for processing OPC UA communication packets. The infinite loop consumes excessive CPU resources and prevents the application from processing legitimate requests, effectively causing a denial of service condition that can persist until the application is manually restarted or the system is rebooted.
The operational impact of CVE-2022-29862 extends beyond simple service disruption to potentially compromise entire industrial control systems and operational technology environments. In manufacturing and process control applications, where OPC UA is commonly deployed for real-time communication between sensors, actuators, and control systems, this vulnerability can lead to production halts, safety system degradation, and cascading failures across interconnected components. The remote exploitability aspect means that attackers can target these systems from external networks without requiring physical access or insider knowledge, making the vulnerability particularly dangerous in environments where security boundaries are not properly enforced. According to CWE classification, this vulnerability maps to CWE-835: Loop with Unreachable Exit Condition, which represents a fundamental programming error where loop termination conditions are either missing or improperly implemented. The flaw also aligns with ATT&CK technique T1499.001: Endpoint Denial of Service, as it specifically targets endpoint systems to cause operational disruption through resource exhaustion.
Organizations should prioritize immediate remediation of this vulnerability by upgrading to a patched version of the OPC UA .NET Standard Stack that addresses the infinite loop condition in message processing. The vendor has released updates that implement proper input validation and termination conditions for message handling routines, preventing the execution path that leads to the infinite loop. Network segmentation and access controls should be implemented to limit exposure of affected systems to untrusted networks, while monitoring systems should be configured to detect unusual CPU utilization patterns that may indicate exploitation attempts. Security teams should also implement defensive measures such as rate limiting for OPC UA communication and regular vulnerability assessments of industrial control system components. The remediation process requires careful planning to ensure that patching does not disrupt critical operations, particularly in environments where OPC UA is integral to safety-critical systems, and should include thorough testing in controlled environments before deployment to production systems.