CVE-2023-49803
8.6 · HIGHOverview
CVE-2023-49803 is a high-severity vulnerability affecting koajs cross-origin_resource_sharing_for_koa. It was published on December 11, 2023 and has a CVSS 3.1 base score of 8.6 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.6, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
@koa/cors npm provides Cross-Origin Resource Sharing (CORS) for koa, a web framework for Node.js. Prior to version 5.0.0, the middleware operates in a way that if an allowed origin is not provided, it will return an `Access-Control-Allow-Origin` header with the value of the origin from the request. This behavior completely disables one of the most crucial elements of browsers - the Same Origin Policy (SOP), this could cause a very serious security threat to the users of this middleware. If such behavior is expected, for instance, when middleware is used exclusively for prototypes and not for production applications, it should be heavily emphasized in the documentation along with an indication of the risks associated with such behavior, as many users may not be aware of it. Version 5.0.0 fixes this vulnerability.
Remediation
Check the references section for vendor advisories and patches from koajs. Update cross-origin_resource_sharing_for_koa 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 |
|---|---|---|---|
| koajs | cross-origin_resource_sharing_for_koa | >= 0, < 5.0.0 | Affected |
References
Frequently Asked Questions
What is CVE-2023-49803?
CVE-2023-49803 is a high-severity vulnerability affecting koajs cross-origin_resource_sharing_for_koa. It was published on December 11, 2023 and has a CVSS 3.1 base score of 8.6 (HIGH).
How severe is CVE-2023-49803?
This vulnerability has a CVSS 3.1 base score of 8.6, 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-2023-49803?
Check the references section for vendor advisories and patches from koajs. Update cross-origin_resource_sharing_for_koa 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-2023-49803?
CyberStrike's AI-powered security agents can automatically detect CVE-2023-49803 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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