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Prefix escape

Critical severity GitHub Reviewed Published Feb 23, 2021 in fastify/fastify-reply-from • Updated Feb 1, 2023

Package

npm fastify-reply-from (npm)

Affected versions

< 4.0.2

Patched versions

4.0.2

Description

Impact

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. Unfortunately, it is.

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

Patches

A patch have been submitted by Corey Farrell git@cfware.com, the reporter.
All releases after v4.0.2 include the fix.

Workarounds

There are no workaround available.

For more information

If you have any questions or comments about this advisory:

References

@mcollina mcollina published to fastify/fastify-reply-from Feb 23, 2021
Reviewed Mar 2, 2021
Published by the National Vulnerability Database Mar 2, 2021
Published to the GitHub Advisory Database Mar 3, 2021
Last updated Feb 1, 2023

Severity

Critical
10.0
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Weaknesses

CVE ID

CVE-2021-21321

GHSA ID

GHSA-qmw8-3v4g-gwj4

Source code

No known source code
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