CVE-2025-26678
Remediation/Mitigation Strategy: CVE-2025-26678
Vulnerability: Improper Access Control in Windows Defender Application Control (WDAC)
Description: This vulnerability allows an unauthorized attacker to bypass the security features of Windows Defender Application Control (WDAC) locally. This means an attacker can execute unauthorized code or applications despite WDAC policies being in place to prevent such execution.
Severity: High (CVSS v3 Score: 8.4)
Known Exploit: While specific exploit details are not provided in the source, the nature of the vulnerability (“Improper access control…allows an attacker to bypass a security feature”) suggests a local attacker can leverage the vulnerability to:
- Execute blocked applications/scripts.
- Modify system configurations protected by WDAC.
- Potentially gain elevated privileges.
Remediation/Mitigation:
Apply Security Updates: Immediately apply any security patches released by Microsoft specifically addressing CVE-2025-26678. This is the primary and most effective remediation. Monitor Microsoft security advisories for updates.
Review and Harden WDAC Policies:
- Audit Existing Policies: Review current WDAC policies to ensure they are as restrictive as possible without impacting legitimate application functionality. Look for overly permissive rules or gaps in coverage.
- Implement Path Rules Carefully: Path rules should be as specific as possible to avoid unintended bypasses. Use hash-based rules where feasible for greater security.
- Consider Code Integrity Policies: Ensure that Code Integrity policies are enforced and properly configured. Code Integrity helps ensure that only trusted code is allowed to execute.
- Enable Recommended Block Rules: Apply all recommended block rules from Microsoft for WDAC.
- Test Changes: Thoroughly test any changes to WDAC policies in a test environment before deploying to production.
Principle of Least Privilege: Enforce the principle of least privilege by limiting user access rights. Prevent users from running as administrators or having elevated permissions unless absolutely necessary.
Endpoint Detection and Response (EDR): Deploy or enhance existing EDR solutions to detect and respond to malicious activity. EDR can help identify and block attempts to exploit the vulnerability even if WDAC is bypassed. Configure EDR solutions to monitor for suspicious application execution and policy violations.
Regular Security Audits: Conduct regular security audits to identify and address vulnerabilities in the system, including misconfigurations of WDAC.
User Awareness Training: Educate users about the risks of running untrusted software and the importance of following security best practices.
Assigner
- Microsoft Corporation [email protected]
Date
- Published Date: 2025-04-08 17:23:55
- Updated Date: 2025-04-08 18:15:52