Cyber Resilience

CVE-2023-49803

High

Published: 11 December 2023

Published
11 December 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
EPSS Score 0.0013 32.2th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-49803 is a high-severity Origin Validation Error (CWE-346) vulnerability in Koajs Cross-Origin Resource Sharing For Koa. Its CVSS base score is 8.6 (High).

Operationally, ranked at the 32.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

@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…

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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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

koajs
cross-origin resource sharing for koa
≤ 5.0.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-346

Requires unique identification of the service before communications, addressing failures to validate the origin of the interaction.

addresses: CWE-346

Trusted path establishment enforces validation that the communication originates from and reaches only the intended trusted system components.

addresses: CWE-346

Enforces validation of the true origin of DNS responses via signatures and chain-of-trust mechanisms.

addresses: CWE-346

Enforces origin validation of name/address data, eliminating reliance on unverified or impersonated DNS sources.

addresses: CWE-346

Mandates origin validation so that only legitimate endpoints can continue the authenticated session.

References