CVE-2021-43803
7.5 · HIGHOverview
CVE-2021-43803 is a high-severity vulnerability affecting vercel next.js. It was published on December 10, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Next.js is a React framework. In versions of Next.js prior to 12.0.5 or 11.1.3, invalid or malformed URLs could lead to a server crash. In order to be affected by this issue, the deployment must use Next.js versions above 11.1.0 and below 12.0.5, Node.js above 15.0.0, and next start or a custom server. Deployments on Vercel are not affected, along with similar environments where invalid requests are filtered before reaching Next.js. Versions 12.0.5 and 11.1.3 contain patches for this issue.
Remediation
Check the references section for vendor advisories and patches from vercel. Update next.js 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 |
|---|---|---|---|
| vercel | next.js | >= 11.1.0, < 11.1.3 | Affected |
References
Frequently Asked Questions
What is CVE-2021-43803?
CVE-2021-43803 is a high-severity vulnerability affecting vercel next.js. It was published on December 10, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2021-43803?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-43803?
Check the references section for vendor advisories and patches from vercel. Update next.js 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-2021-43803?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-43803 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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