CVE-2023-42465 is a vulnerability identified in sudo versions before 1.9.15, where the application logic for handling error codes is flawed. Specifically, sudo sometimes determines authentication success or failure by checking that a return value does not equal an error code, rather than explicitly confirming a success code. This logic, combined with the fact that the error codes used do not have protections against single-bit flips, opens the door for row hammer attacks. Row hammer is a hardware-based attack that induces bit flips in memory by repeatedly accessing adjacent memory rows, potentially altering critical data. In this context, an attacker capable of inducing bit flips in the memory storing sudo's error codes could cause sudo to misinterpret an error as a success, thereby bypassing authentication or escalating privileges. This vulnerability is particularly dangerous because it leverages hardware faults rather than software bugs alone, making traditional software defenses less effective. Although no public exploits have been reported yet, the widespread use of sudo in Unix-like systems, including Linux distributions common in European organizations, means the attack surface is large. The lack of a CVSS score indicates that the vulnerability is newly published and not yet fully assessed, but the technical details suggest a significant risk. The vulnerability requires local access to the system to induce the row hammer effect, but no user interaction or prior authentication is necessary once access is obtained. The complexity of performing a row hammer attack varies depending on hardware and system configuration, but recent research has demonstrated its feasibility on commodity hardware. The vulnerability highlights the need for both software patches and hardware-level mitigations to prevent bit flips. Since sudo is a critical component for privilege management, successful exploitation could lead to full system compromise.

For European organizations, the impact of CVE-2023-42465 could be severe. Sudo is a fundamental utility used to grant elevated privileges on Unix-like systems, including Linux servers that underpin much of Europe's IT infrastructure. Exploitation could allow attackers to bypass authentication mechanisms or escalate privileges to root, leading to unauthorized access, data breaches, and potential disruption of services. Critical sectors such as finance, healthcare, government, and energy, which rely heavily on Linux-based systems, could face significant operational and reputational damage. The hardware-based nature of the attack means that traditional software security controls may be insufficient, increasing the risk of stealthy compromise. Additionally, the vulnerability could be leveraged in multi-stage attacks where initial low-privilege access is escalated to full control. Given the prevalence of sudo and the difficulty in detecting row hammer attacks, organizations may face challenges in timely detection and response. The lack of known exploits in the wild currently reduces immediate risk, but the potential for future exploitation remains high. Overall, the vulnerability threatens confidentiality, integrity, and availability of affected systems.

To mitigate CVE-2023-42465, European organizations should immediately upgrade sudo to version 1.9.15 or later, where the logic flaw has been corrected. In addition to patching, organizations should implement hardware-level protections against row hammer attacks, such as enabling Error-Correcting Code (ECC) memory where possible, applying firmware updates that include memory refresh rate improvements, and using memory modules with built-in row hammer mitigation. System administrators should audit and restrict physical and local access to critical systems to reduce the risk of attackers inducing row hammer effects. Monitoring for unusual sudo behavior or privilege escalations can help detect exploitation attempts. Employing virtualization or containerization can also limit the impact of compromised sudo processes. Finally, organizations should stay informed about developments in row hammer attack techniques and adjust defenses accordingly. Regular security assessments and penetration testing focusing on hardware fault attacks can help identify residual risks.