CVE-2022-21971
Microsoft Windows Runtime Remote Code Execution Vulnerability
Description
CVE-2022-21971 is a remote code execution vulnerability in the Microsoft Windows Runtime that allows an attacker to execute arbitrary code on affected Windows systems. The vulnerability exists due to an unspecified flaw in the Windows Runtime component, which handles core application execution functionality in the operating system. CISA has added CVE-2022-21971 to its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. With an EPSS score of 87.1% (99.4th percentile), this vulnerability has an extremely high probability of exploitation and should be treated as a critical priority for patching.
KEV Information
CVSS Score
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | windows 10 1809 | < 10.0.17763.2565 |
| microsoft | windows 10 1909 | < 10.0.18363.2094 |
| microsoft | windows 10 20h2 | < 10.0.19042.1526 |
| microsoft | windows 10 21h1 | < 10.0.19043.1526 |
| microsoft | windows 10 21h2 | < 10.0.19044.1526 |
| microsoft | windows 11 21h2 | < 10.0.22000.493 |
| microsoft | windows server 2019 | < 10.0.17763.2565 |
| microsoft | windows server 2022 | < 10.0.20348.524 |
| microsoft | windows server 20h2 | < 10.0.19042.1526 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-21971(Patch, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-21971(US Government Resource)
Weakness Type
CWE-20: Improper Input Validation
While the specific technical mechanism of CVE-2022-21971 has not been publicly detailed by Microsoft, the vulnerability in the Windows Runtime component involves improper handling of input that can be leveraged for remote code execution. The Windows Runtime fails to adequately validate or sanitize certain inputs, allowing an attacker to trigger code execution through specially crafted requests or data.
Learn more: CWE-20 — Improper Input Validation
Impact Analysis
CVE-2022-21971 poses a severe threat to Microsoft Windows environments, as the remote code execution capability allows an attacker to fully compromise affected systems. The Windows Runtime is a fundamental component of the operating system, and exploitation can lead to complete loss of confidentiality through data theft, integrity through system modification, and availability through service disruption or ransomware deployment. The EPSS score of 87.1% (99.4th percentile) places this vulnerability among the most likely to be exploited across all tracked CVEs, indicating that threat actors are actively seeking to leverage this flaw. Organizations running unpatched Windows systems face significant risk of compromise, particularly in internet-facing or user-interactive scenarios.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2022-21971 in the wild by adding it to the Known Exploited Vulnerabilities catalog on August 18, 2022, with a remediation deadline of September 8, 2022. The EPSS score of 87.1% (99.4th percentile) indicates extremely high exploitation probability, placing this vulnerability in the top tier of actively exploited flaws. The remote code execution capability in a core Windows component makes this an attractive target for both opportunistic and targeted attacks, and the high EPSS score suggests widespread exploitation tools and techniques are available to threat actors.
Remediation
- Apply Microsoft security updates immediately: Install the patches from Microsoft's February 2022 security updates that address CVE-2022-21971, as referenced in the Microsoft Security Update Guide.
- Prioritize internet-facing and user-interactive Windows systems: Focus patching efforts on systems that are most likely to be targeted, including workstations, terminal servers, and systems exposed to the internet.
- Implement network segmentation: Isolate critical Windows systems behind network segmentation to limit the blast radius of potential exploitation until patches can be applied.
- Enable advanced threat detection: Configure endpoint detection and response (EDR) solutions to monitor for exploitation indicators associated with Windows Runtime abuse, including unusual process creation and code execution patterns.
- Review Windows Event Logs for exploitation indicators: Check for suspicious activity patterns in Windows Event Logs that may indicate attempted or successful exploitation of the Windows Runtime vulnerability.
Technical Details
CVE-2022-21971 is a remote code execution vulnerability in the Microsoft Windows Runtime, a core operating system component that provides the execution environment for Windows applications. While Microsoft has not disclosed the precise technical mechanism, the vulnerability allows an attacker to trigger arbitrary code execution through the Windows Runtime by exploiting an unspecified flaw in how the component processes certain operations. The remote attack vector indicates that exploitation can occur over the network without requiring physical access to the target system. The EPSS score of 87.1% and the inclusion in the CISA KEV catalog confirm that this vulnerability is being actively exploited, with the Windows Runtime's central role in the operating system making successful exploitation particularly impactful, as it can provide the attacker with broad access to system resources and capabilities.
Frequently Asked Questions
Is CVE-2022-21971 being actively exploited?
Yes. CISA has confirmed active exploitation by adding CVE-2022-21971 to the Known Exploited Vulnerabilities catalog. The EPSS score of 87.1% (99.4th percentile) indicates extremely high exploitation activity. Organizations should apply patches immediately.
What products are affected by CVE-2022-21971?
CVE-2022-21971 affects Microsoft Windows through the Windows Runtime component. Multiple Windows versions are potentially affected. Refer to the Microsoft Security Update Guide for the specific list of affected Windows versions and editions.
How do I fix CVE-2022-21971?
Apply the security updates from Microsoft's February 2022 Patch Tuesday that address CVE-2022-21971. Ensure all affected Windows systems are updated through Windows Update, WSUS, or your patch management solution. Prioritize internet-facing systems and user workstations.
How severe is CVE-2022-21971?
CVE-2022-21971 is an extremely severe remote code execution vulnerability with an EPSS score of 87.1% (99.4th percentile), indicating near-certain exploitation. The vulnerability affects a core Windows component and can lead to complete system compromise. The combination of remote exploitability and confirmed active exploitation makes this one of the highest-priority Windows vulnerabilities to patch.
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