CVE-2023-5855 is a use-after-free vulnerability identified in the Reading Mode feature of Google Chrome versions prior to 119.0.6045.105. This vulnerability arises due to improper memory management where a previously freed object is accessed, leading to potential heap corruption. Exploitation requires a remote attacker to convince a user to perform specific user interface gestures, which triggers the use-after-free condition. The vulnerability affects the Chromium rendering engine's handling of Reading Mode, a feature designed to simplify web page content for easier reading. Successful exploitation can result in arbitrary code execution, allowing an attacker to compromise the confidentiality, integrity, and availability of the affected system. The CVSS 3.1 base score is 8.8, indicating a high severity level, with attack vector being network-based (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is necessary (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). No known exploits in the wild have been reported as of the publication date (November 1, 2023). The vulnerability is categorized under CWE-416 (Use After Free), a common memory corruption issue that can lead to serious security breaches if exploited. Given the nature of the vulnerability, it is critical for users and organizations to update Chrome to version 119.0.6045.105 or later to mitigate the risk.

For European organizations, the impact of CVE-2023-5855 can be significant due to the widespread use of Google Chrome as a primary web browser across enterprises, government agencies, and critical infrastructure sectors. Exploitation could lead to remote code execution, enabling attackers to deploy malware, steal sensitive data, or disrupt operations. The requirement for user interaction (specific UI gestures) means targeted phishing or social engineering campaigns could be used to trigger the vulnerability. Sectors such as finance, healthcare, and public administration, which handle sensitive personal and financial data, are particularly at risk. Additionally, the vulnerability could be leveraged as an initial foothold in a multi-stage attack chain, potentially compromising internal networks. The high impact on confidentiality, integrity, and availability underscores the threat to data protection compliance under GDPR and other regulatory frameworks in Europe. Although no exploits are currently known in the wild, the high CVSS score and ease of exploitation suggest that threat actors may develop exploits rapidly, increasing the urgency for mitigation.

1. Immediate patching: Organizations should prioritize updating all instances of Google Chrome to version 119.0.6045.105 or later. Automated patch management tools can help ensure rapid deployment across large environments. 2. User awareness training: Educate users about the risks of interacting with untrusted web content and the importance of avoiding suspicious links or UI interactions that could trigger the vulnerability. 3. Browser hardening: Disable or restrict the use of Reading Mode via group policies or enterprise browser management tools if patching cannot be immediately applied. 4. Network controls: Implement web filtering and intrusion detection systems to monitor and block malicious websites or payloads that could exploit this vulnerability. 5. Endpoint protection: Ensure advanced endpoint detection and response (EDR) solutions are in place to detect anomalous behavior indicative of exploitation attempts. 6. Incident response readiness: Prepare for potential exploitation by updating incident response playbooks to include detection and containment strategies specific to Chrome-based attacks. 7. Monitor threat intelligence feeds for emerging exploit reports related to CVE-2023-5855 to adapt defenses promptly.