CVE-2025-13032 is a critical security vulnerability identified in Avast Antivirus products (Free, Premium, Ultimate editions) on Windows platforms prior to version 25.3. The root cause is a TOCTOU race condition categorized under CWE-367, specifically a double fetch issue within the sandbox kernel driver component. This flaw allows a local attacker with limited privileges to trigger a pool overflow by exploiting the timing window between the kernel driver's verification of data and its actual use. The race condition enables the attacker to manipulate kernel memory allocations, leading to arbitrary code execution with elevated privileges. This escalation can compromise the entire system, granting the attacker SYSTEM-level access, thereby affecting confidentiality, integrity, and availability of the host. The vulnerability requires local access but no user interaction, making it particularly dangerous in environments where multiple users share systems or where attackers have gained limited footholds. Although no exploits are currently known in the wild, the CVSS v3.1 score of 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) reflects the high ease of exploitation and severe impact. The vulnerability is especially critical because it targets a security product designed to protect systems, potentially undermining trust and security posture. The lack of an available patch at the time of publication necessitates immediate risk mitigation strategies.

For European organizations, this vulnerability poses a significant threat due to the widespread use of Avast antivirus solutions across enterprises, SMBs, and personal devices. Successful exploitation can lead to full system compromise, enabling attackers to bypass security controls, steal sensitive data, disrupt operations, or deploy ransomware. Critical sectors such as finance, healthcare, government, and energy are particularly vulnerable given their reliance on endpoint protection and the potential impact of system breaches. The local privilege escalation aspect means that attackers who have gained initial access through phishing, insider threats, or other means can leverage this vulnerability to deepen their control. Moreover, the vulnerability undermines the integrity of the antivirus solution itself, potentially allowing attackers to disable or evade detection mechanisms. This could lead to prolonged undetected intrusions and increased risk of data breaches. The absence of known exploits in the wild provides a window for proactive defense, but the critical severity demands urgent attention.

1. Immediately restrict local user permissions to the minimum necessary, especially on shared or multi-user systems, to reduce the risk of local exploitation. 2. Monitor kernel driver behavior and system logs for anomalies indicative of race condition exploitation or pool overflow attempts. 3. Implement application whitelisting and endpoint detection and response (EDR) solutions that can detect unusual privilege escalation activities. 4. Prepare for rapid deployment of the official patch from Avast once released; subscribe to vendor advisories and threat intelligence feeds for updates. 5. Conduct internal audits to identify systems running vulnerable Avast versions and prioritize them for remediation. 6. Educate users about the risks of local privilege escalation and enforce strict controls on software installation and execution. 7. Consider temporary use of alternative antivirus solutions with no known vulnerabilities if patching is delayed. 8. Employ network segmentation to limit lateral movement in case of compromise. 9. Regularly back up critical data and verify backup integrity to mitigate impact of potential ransomware attacks following exploitation.