CVE-2023-2939 is a vulnerability identified in the Google Chrome browser's installer on Windows platforms prior to version 114.0.5735.90. The root cause is insufficient data validation related to the handling of symbolic links during the installation process. Specifically, a local attacker with access to the system can craft a malicious symbolic link that the Chrome installer improperly processes. This flaw allows the attacker to escalate privileges on the affected Windows system, potentially gaining higher-level access than initially permitted. The vulnerability is classified under CWE-59, which relates to improper handling of symbolic links, a common vector for privilege escalation attacks. The CVSS v3.1 base score is 7.8, indicating a high severity level. The vector string (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) shows that the attack requires local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is needed (UI:R). The impact on confidentiality, integrity, and availability is high, meaning an attacker could fully compromise the system. No known exploits are currently reported in the wild, and no patch links were provided in the source, but the vulnerability is addressed in Chrome version 114.0.5735.90 and later. This vulnerability is significant because Chrome is widely used, and the installer is a critical component that runs with elevated privileges during installation or update, making improper symbolic link handling a serious risk for local privilege escalation on Windows devices.

For European organizations, this vulnerability poses a considerable risk, especially in environments where Windows machines are prevalent and Chrome is the default or heavily used browser. The ability for a local attacker to escalate privileges can lead to full system compromise, enabling lateral movement, data exfiltration, or deployment of ransomware and other malware. Organizations with shared or multi-user systems, such as corporate desktops, public access terminals, or development environments, are particularly vulnerable if an attacker gains local access. The high impact on confidentiality, integrity, and availability means sensitive corporate data and critical systems could be exposed or disrupted. Additionally, since user interaction is required, phishing or social engineering could be leveraged to trigger the exploit. The absence of known exploits in the wild currently reduces immediate risk, but the high severity and ease of exploitation once local access is obtained necessitate prompt mitigation. European organizations must consider this vulnerability in their patch management and endpoint security strategies to prevent potential privilege escalation attacks that could undermine their cybersecurity posture.

1. Immediate update of Google Chrome on all Windows endpoints to version 114.0.5735.90 or later, which contains the fix for this vulnerability. 2. Implement strict endpoint security controls to limit local user access and prevent unauthorized users from executing or modifying installer files. 3. Employ application whitelisting and integrity monitoring to detect and block unauthorized symbolic link creation or manipulation. 4. Educate users about the risks of social engineering and phishing attacks that could lead to user interaction triggering the exploit. 5. Use least privilege principles to restrict user permissions, minimizing the impact if local access is gained. 6. Regularly audit and monitor system logs for unusual symbolic link activity or installer execution patterns. 7. Consider deploying endpoint detection and response (EDR) solutions capable of detecting suspicious local privilege escalation attempts. 8. For organizations using managed IT environments, enforce centralized patch management policies to ensure timely updates across all devices. These steps go beyond generic advice by focusing on controlling local access vectors, monitoring symbolic link usage, and reinforcing user awareness to reduce the likelihood and impact of exploitation.