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CVE-2023-51701— @fastify-reply-from JSON Content-Type parsing confusion

Quick assessment

Affected

fastify fastify-reply-from

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Fastify是OpenJS基金会的一款用于Node.js的开源Web框架。 Fastify fastify-reply-from 9.6.0之前版本存在安全漏洞，该漏洞源于使用fastify/reply-from通过header传递正文可能会被误解，导致绕过安全检查。

CVSS 5.3 · Medium EPSS 0.48% · P41 Updated Jun 03, 2025

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

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I. Basic Information for CVE-2023-51701

Vulnerability Information

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Vulnerability Title

@fastify-reply-from JSON Content-Type parsing confusion

Source: CVE Program / CVE List V5

Vulnerability Description

fastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. A reverse proxy server built with `@fastify/reply-from` could misinterpret the incoming body by passing an header `ContentType: application/json ; charset=utf-8`. This can lead to bypass of security checks. This vulnerability has been patched in '@fastify/reply-from` version 9.6.0.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

HTTP请求的解释不一致性(HTTP请求私运)

Source: CVE Program / CVE List V5

Vulnerability Title

Fastify 安全漏洞

Source: CNNVD (China National Vulnerability Database)

Vulnerability Description

Source: CNNVD (China National Vulnerability Database)

CVSS Information

N/A

Source: CNNVD (China National Vulnerability Database)

Vulnerability Type

N/A

Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
fastify	fastify-reply-from	< 9.6.0	-

II. Public POCs for CVE-2023-51701

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2023-51701

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Vendor Advisories for CVE-2023-51701 (1)

https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v2v2-hph8-q5xp x_refsource_CONFIRM

Other References for CVE-2023-51701 (1)

https://github.com/fastify/fastify-reply-from/releases/tag/v9.6.0 x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2023-51701

IV. Related Vulnerabilities

Same product: fastify-reply-from

Same vendor: fastify

Same weakness: CWE-444