CVE-2023-49803

High

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.

SeverityHigh
CVSS8.6
Exploit probability—
ProductKoajs Cross-origin Resource Sharing For Koa
PublishedDec 11, 2023
First seenDec 11, 2023
Weakness typeCWE-346CWE-346

How to fix

Update
  • koajs cross-origin_resource_sharing_for_koa5.0.0 or later
  • @koa/cors5.0.0 or later

Affected products

ProductAffected versionsFixed in
koajs cross-origin_resource_sharing_for_koav < 5.0.05.0.0
@koa/corsnpmv < 5.0.05.0.0

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