CVE-2021-21284
6.8 · MEDIUMOverview
CVE-2021-21284 is a medium-severity vulnerability affecting docker docker. It was published on February 2, 2021 and has a CVSS 3.1 base score of 6.8 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.8, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.
Remediation
Check the references section for vendor advisories and patches from docker. Update docker 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 |
|---|---|---|---|
| docker | docker | >= 0, < 19.03.15 | Affected |
| netapp | e-series_santricity_os_controller | 11.0.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-21284?
CVE-2021-21284 is a medium-severity vulnerability affecting docker docker. It was published on February 2, 2021 and has a CVSS 3.1 base score of 6.8 (MEDIUM).
How severe is CVE-2021-21284?
This vulnerability has a CVSS 3.1 base score of 6.8, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-21284?
Check the references section for vendor advisories and patches from docker. Update docker 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-2021-21284?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-21284 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.
Automated penetration testing that runs continuously, not just quarterly.
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