CVE-2023-41185 in UaGateway
Summary
by MITRE • 05/03/2024
Unified Automation UaGateway Certificate Parsing Integer Overflow Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Unified Automation UaGateway. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the processing of client certificates. When parsing the certificate length field, the process does not properly validate user-supplied data, which can result in an integer overflow. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20353.
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Analysis
by VulDB Data Team • 08/08/2025
The vulnerability CVE-2023-41185 affects Unified Automation UaGateway software, representing a critical integer overflow issue within the certificate parsing mechanism that enables remote attackers to induce denial-of-service conditions without requiring authentication. This weakness resides in the handling of client certificate length fields during the certificate processing workflow, where insufficient input validation allows maliciously crafted certificate data to trigger unexpected behavior in the underlying integer arithmetic operations.
The technical flaw manifests when the UaGateway application processes certificate data structures containing malformed length fields that exceed the maximum representable value for the integer data type used in the parsing routine. This integer overflow condition occurs during the certificate validation process where the application attempts to allocate memory or perform calculations based on the parsed certificate length value. When the length field contains a value that, when processed, exceeds the maximum value that can be represented by the integer type, the overflow causes the application to behave unpredictably, potentially leading to memory corruption or system instability.
This vulnerability operates under the Common Weakness Enumeration framework as CWE-190, which specifically addresses integer overflow conditions that occur when a computation is performed on a signed integer with a value that exceeds the maximum representable value for that integer type. The attack vector requires only remote access to the affected service, making it particularly dangerous as attackers can exploit this without needing to authenticate or gain physical access to the system. The lack of authentication requirements significantly increases the attack surface and potential impact.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire gateway functionality, as the integer overflow can cause the application to crash or enter an unstable state from which it cannot recover automatically. This denial-of-service condition affects all versions of Unified Automation UaGateway that are vulnerable to this specific integer overflow in certificate parsing, potentially disrupting industrial automation and control systems that rely on OPC UA communication protocols. The affected systems may experience complete service unavailability until manual intervention or system restart occurs.
Mitigation strategies for this vulnerability should include immediate application of vendor-provided patches or updates that address the integer overflow in certificate processing routines. Organizations should also implement network segmentation and access controls to limit exposure of the UaGateway service to untrusted networks. Monitoring for unusual certificate processing patterns or service disruptions can help detect exploitation attempts. Additionally, implementing certificate validation policies that restrict the types of certificates accepted by the gateway and deploying intrusion detection systems that can identify malformed certificate data can provide additional defense-in-depth measures. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial-of-service attacks, and represents a critical security gap that requires immediate attention in industrial control systems environments where UaGateway is deployed.