CVE-2021-41380
6.5 · MEDIUMOverview
CVE-2021-41380 is a medium-severity vulnerability affecting realvnc vnc_viewer. It was published on September 17, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
RealVNC Viewer 6.21.406 allows remote VNC servers to cause a denial of service (application crash) via crafted RFB protocol data. NOTE: It is asserted that this issue requires social engineering a user into connecting to a fake VNC Server. The VNC Viewer application they are using will then hang, until terminated, but no memory leak occurs - the resources are freed once the hung process is terminated and the resource usage is constant during the hang. Only the process that is connected to the fake Server is affected. This is an application bug, not a security issue
Remediation
Check the references section for vendor advisories and patches from realvnc. Update vnc_viewer to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
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Frequently Asked Questions
What is CVE-2021-41380?
CVE-2021-41380 is a medium-severity vulnerability affecting realvnc vnc_viewer. It was published on September 17, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2021-41380?
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-41380?
Check the references section for vendor advisories and patches from realvnc. Update vnc_viewer to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-41380?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-41380 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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