SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-21321

fastify-reply-from is an npm package which is a fastify plugin to forward the current http request to another server.

CRITICAL 10.0EPSS 1.82%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.82%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS
1.82% probability · 78th percentile
CISA KEV
Not listed
Weakness
CWE-20
Affected
fastify-reply-from project/fastify-reply-from
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.