CVE-2022-41049
Microsoft Windows Mark of the Web (MOTW) Security Feature Bypass Vulnerability
Description
CVE-2022-41049 is a security feature bypass vulnerability in the Windows Mark of the Web (MotW) mechanism that affects a wide range of Microsoft Windows versions including Windows 10, Windows 11, and Windows Server editions. This vulnerability allows an attacker to craft files that bypass the Mark of the Web security tagging, which normally warns users when opening files downloaded from the internet or received via email. With a CVSS score of 5.4 (Medium) and an EPSS score of 13.1% (94th percentile), CVE-2022-41049 poses a significant risk because it undermines a fundamental Windows security boundary used to protect users from malicious downloaded content. CISA has confirmed active exploitation of this Windows MotW bypass vulnerability and added it to the Known Exploited Vulnerabilities catalog.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:LOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | windows 10 1507 | < 10.0.10240.19567 |
| microsoft | windows 10 1607 | < 10.0.14393.5501 |
| microsoft | windows 10 1809 | < 10.0.17763.3650 |
| microsoft | windows 10 20h2 | < 10.0.19042.2251 |
| microsoft | windows 10 21h1 | < 10.0.19043.2251 |
| microsoft | windows 10 21h2 | < 10.0.19044.2251 |
| microsoft | windows 10 22h2 | < 10.0.19045.2251 |
| microsoft | windows 11 21h2 | < 10.0.22000.1219 |
| microsoft | windows 11 22h2 | < 10.0.22621.819 |
| microsoft | windows server 2016 | < 10.0.14393.5501 |
| microsoft | windows server 2019 | < 10.0.17763.3650 |
| microsoft | windows server 2022 | < 10.0.20348.1249 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-41049(Patch, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-41049(US Government Resource)
Weakness Type
Security Feature Bypass
CVE-2022-41049 does not map to a specific CWE identifier. The vulnerability represents a bypass of Windows Mark of the Web (MotW), a security feature that tags files downloaded from the internet with a zone identifier. When MotW is bypassed, files that should trigger security warnings and restricted execution are instead treated as trusted local content, removing a critical layer of user protection against malicious downloads.
Impact Analysis
CVE-2022-41049 is remotely exploitable without physical access and with low attack complexity, though it requires user interaction in the form of opening a malicious file. No authentication or privileges are needed to deliver the exploit. Confidentiality (None): This vulnerability does not directly expose confidential data. Integrity (Low): The bypass undermines the integrity of the Windows security model by allowing files to evade MotW tagging, which normally restricts how downloaded files can execute. This enables subsequent attacks such as macro execution in Office documents or script execution that would otherwise be blocked. Availability (Low): While the direct availability impact is limited, the bypass facilitates follow-on attacks that could significantly impact system availability. With a CVSS score of 5.4 (Medium), this vulnerability is deceptively dangerous because it is often used as a component in multi-stage attack chains, where bypassing MotW is the first step before deploying malware or ransomware payloads that would normally be blocked by Windows security features.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2022-41049 in the wild and has included it in the Known Exploited Vulnerabilities catalog with a remediation deadline of December 9, 2022. The EPSS score of 13.1% (94th percentile) indicates a high probability of exploitation activity, consistent with MotW bypass vulnerabilities being highly valued by threat actors for use in phishing campaigns and malware delivery. Mark of the Web bypass vulnerabilities are frequently chained with other exploitation techniques, as removing the MotW protection allows malicious macros, scripts, and executables to run without triggering Windows security prompts.
Remediation
- Apply Microsoft security updates immediately as directed by CISA: "Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable." Install the patches from the Microsoft Security Response Center for all affected Windows versions.
- Patch all affected Windows versions including Windows 10 (versions 1507, 1607, 1809, 20H2, 21H1, 21H2, 22H2), Windows 11 (21H2, 22H2), Windows Server 2016, Windows Server 2019, and Windows Server 2022. Use Windows Update, WSUS, or your patch management solution to deploy updates across your environment.
- Implement additional email and web gateway protections that inspect downloaded files independently of MotW tagging. Configure email security solutions to block or quarantine suspicious file types commonly used in MotW bypass attacks, such as ISO files, ZIP archives, and Office documents with macros.
- Review and enforce Attack Surface Reduction (ASR) rules in Microsoft Defender for Endpoint, specifically rules that block Office applications from creating child processes, block execution of potentially obfuscated scripts, and block untrusted and unsigned processes from running from USB. These rules provide defense-in-depth even when MotW is bypassed.
- Educate users about the risks of opening unexpected files, even when security warnings are not displayed. Implement application control policies (such as Windows Defender Application Control or AppLocker) to restrict which executables and scripts can run, providing protection independent of MotW.
Technical Details
CVE-2022-41049 is a security feature bypass vulnerability in the Windows Mark of the Web (MotW) mechanism. MotW is implemented through NTFS alternate data streams (ADS), specifically the Zone.Identifier stream, which is attached to files downloaded from the internet or other untrusted sources. When this zone identifier is present, Windows and applications like Microsoft Office apply additional security restrictions such as Protected View, macro blocking, and SmartScreen warnings. The vulnerability in CVE-2022-41049 allows an attacker to craft files that circumvent the proper application of MotW tagging, so that malicious files are treated as if they originated from a trusted local source. As reflected in the CVSS vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L), the attack requires network delivery and user interaction, with low impacts to integrity and availability but no direct confidentiality impact. The primary danger lies in enabling downstream attacks that exploit the absence of security restrictions.
Frequently Asked Questions
Is CVE-2022-41049 being actively exploited?
Yes, CVE-2022-41049 is being actively exploited in the wild. CISA has included it in the Known Exploited Vulnerabilities catalog with a remediation deadline of December 9, 2022. The EPSS score of 13.1% places it in the 94th percentile for exploitation probability.
What products are affected by CVE-2022-41049?
CVE-2022-41049 affects a broad range of Microsoft Windows versions: Windows 10 (versions 1507, 1607, 1809, 20H2, 21H1, 21H2, 22H2), Windows 11 (versions 21H2, 22H2), Windows Server 2016, Windows Server 2019, and Windows Server 2022.
How do I fix CVE-2022-41049?
Install the security updates from Microsoft for all affected Windows versions through Windows Update, WSUS, or your enterprise patch management solution. Additionally, implement Attack Surface Reduction rules and email gateway protections to provide defense-in-depth against MotW bypass attacks. See the Remediation section for detailed steps.
How severe is CVE-2022-41049?
CVE-2022-41049 is rated Medium with a CVSS score of 5.4 out of 10. However, its severity is amplified by its role in attack chains where it enables malware, macros, and scripts to execute without security warnings. The EPSS score of 13.1% (94th percentile) confirms significant exploitation activity.
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