// For flags

CVE-2021-21321

Prefix escape

Severity Score

10.0
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

fastify-reply-from is an npm package which is a fastify plugin to forward the current http request to another server. In fastify-reply-from before version 4.0.2, by crafting a specific URL, it is possible to escape the prefix of the proxied backend service. If the base url of the proxied server is "/pub/", a user expect that accessing "/priv" on the target service would not be possible. In affected versions, it is possible. This is fixed in version 4.0.2.

fastify-reply-from es un paquete npm que es un plugin fastify para reenviar la petición http actual a otro servidor. En fastify-reply-from anterior a la versión 4.0.2, al diseñar una URL específica, es posible escapar del prefijo del servicio de backend proxy. Si la URL base del servidor proxy es "/pub/", el usuario espera que no sea posible acceder a "/priv" en el servicio de destino. En versiones afectadas, es posible. Esto se corrige en la versión 4.0.2

A flaw was found in fastify-reply-from. Escaping of the prefix of the proxied backend service is possible allowing an attacker, using a specially crafted URL, to gain access to directories that would otherwise be out of bounds. The highest threat from this vulnerability is to data confidentiality and integrity.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-12-22 CVE Reserved
  • 2021-03-02 CVE Published
  • 2024-07-20 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Fastify-reply-from Project
Search vendor "Fastify-reply-from Project"
 Fastify-reply-from
Search vendor "Fastify-reply-from Project" for product "Fastify-reply-from"
 < 4.0.2
Search vendor "Fastify-reply-from Project" for product "Fastify-reply-from" and version " < 4.0.2"
node.js
Affected