Vulnerability · Published Dec 11, 2023 · Assigned by GitHub_M
CVE-2023-49803@koa/cors has overly permissive origin policy
High 8.6
In plain English
A high-severity security flaw in cors from koajs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @koa/cors | 5.0.0 | GHSA-qxrj-hx23-xp82 |
Affected products (as reported)
Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
References
- https://github.com/koajs/cors/security/advisories/GHSA-qxrj-hx23-xp82 x_refsource_CONFIRM
- https://github.com/koajs/cors/commit/f31dac99f5355c41e7d4dd3c4a80c5f154941a11 x_refsource_MISC