Improper input validation in Fastify Fastify-Http-Proxy

CVE-2021-21322

fastify-http-proxy is an npm package which is a fastify plugin for proxying your http requests to another server, with hooks. 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 4.3.1.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.016 (75.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 75.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-21322: held from 0.016 to 0.016.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-21322?
CVE-2021-21322 is a critical-severity vulnerability in Fastify Fastify-Http-Proxy, classified under Improper Input Validation. CVSS score: 10.0/10. Published 2021-03-02.
How severe is CVE-2021-21322?
Critical severity. CVSS v3 base score is 10.0 out of 10.
Is CVE-2021-21322 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.