@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.
History

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2023-12-11T22:42:17.547Z

Updated: 2024-08-02T22:01:26.009Z

Reserved: 2023-11-30T13:39:50.865Z

Link: CVE-2023-49803

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2023-12-11T23:15:07.620

Modified: 2024-11-21T08:33:52.570

Link: CVE-2023-49803

cve-icon Redhat

No data.