CVE-2025-21366 is a high-severity remote code execution vulnerability in Microsoft Access and related Microsoft products. This vulnerability allows attackers to execute arbitrary code on affected installations, potentially leading to severe consequences such as unauthorized access to sensitive data. The vulnerability has a CVSS score of 7.8, indicating a high level of risk, and is classified under CWE-416.
The vulnerability was published on January 14, 2025, and remains a significant concern for organizations utilizing affected Microsoft products. The exploitability of this vulnerability is classified as high, and without proper mitigation, organizations face potential exploitation risks.
Risk to organizations includes unauthorized access, data breaches, and the potential for further exploits if the vulnerability is not addressed. Organizations should prioritize patching immediately to safeguard their systems and data.
Currently, there are no known public exploits or proof of concept code available for this vulnerability. However, the nature of remote code execution vulnerabilities makes them particularly dangerous, and organizations must remain vigilant.
Considering the potential impact and the severity of the vulnerability, organizations should address this in their priority patch cycle to minimize the risk of exploitation.
Vulnerability Details
The official description of CVE-2025-21366 is a "Microsoft Access Remote Code Execution Vulnerability." The vulnerability is classified as a remote code execution issue with a CVSS score of 7.8, categorized as high severity. This vulnerability affects various Microsoft products, including Microsoft 365 Apps, Microsoft Access 2016, and the Office Long Term Servicing Channel versions 2021 and 2024.
The vulnerability was first published on January 14, 2025, and is classified under CWE-416. Organizations using products within the Microsoft ecosystem should be aware of this vulnerability and take necessary actions to mitigate it.
Technical Analysis
The root cause of this vulnerability relates to improper input validation and handling within Microsoft Access. Attackers may exploit this vulnerability by enticing users to open a malicious file that triggers the execution of arbitrary code.
The attack vector is local, and the complexity is low, as the attacker requires user interaction to execute the attack. No privileges are required to exploit this vulnerability, making it even more concerning. The impact on confidentiality, integrity, and availability is high, as successful exploitation can lead to full system compromise.
Risk & Impact Analysis
Real-world deployment risks associated with CVE-2025-21366 include the possibility of unauthorized access to systems and data, especially in environments where Microsoft Access is extensively used. The blast radius potential is significant, as this vulnerability affects multiple product versions and configurations. Organizations must prioritize addressing this vulnerability based on its high CVSS score and exploitability status.
Considering the EPSS score of 0.02064, which places it in a higher percentile, the urgency assessment indicates that organizations should act swiftly to mitigate this vulnerability, making it a top priority in their patch management processes.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of Microsoft products are affected by CVE-2025-21366: Microsoft 365 Apps (both x64 and x86), Microsoft Access 2016, Microsoft Office 2019 (both x64 and x86), and Microsoft Office Long Term Servicing Channel versions 2021 and 2024. Organizations should ensure they are running patched versions to mitigate the risks associated with this vulnerability.
Mitigation & Remediation
To mitigate the risks posed by CVE-2025-21366, organizations should prioritize applying the latest patches provided by Microsoft. It is essential to regularly monitor for updates and ensure all affected products are updated to the latest versions.
If immediate patching is not possible, organizations should implement workarounds such as restricting access to vulnerable systems and enhancing monitoring to detect any unusual behavior. For comprehensive security, organizations may consider utilizing penetration testing to identify further weaknesses in their security posture.
Detection Guidance
Organizations should monitor logs for indicators of exploitation attempts, such as unexpected system behavior following user interactions with potentially malicious files. Additionally, behavioral anomalies that diverge from normal operations can signal potential exploitation.
Network signatures that capture abnormal traffic patterns related to Microsoft Access can aid in the early detection of exploitation attempts. Regular audits and system checks should be conducted to ensure that no unauthorized changes have been made.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-21366 lies in its representation of ongoing security challenges in widely-used software. Remote code execution vulnerabilities remain a critical concern, often exploited in broader attack campaigns.
Organizations should leverage this incident to enhance their security posture, focusing on robust patch management and user training to recognize malicious files. Security teams should also analyze the patterns that led to this vulnerability's discovery and ensure similar weaknesses are not present in their systems.
Strategically, organizations should adopt a proactive approach to security, integrating regular security assessments such as application security assessments into their development lifecycles to uncover and remediate vulnerabilities before they can be exploited.
Furthermore, organizations can benefit from implementing a continuous penetration testing strategy to ensure ongoing awareness of potential vulnerabilities in their systems.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)