Prefix escape
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:
- Open an issue in fastify-reply-from
- Email us at hello@matteocollina.com
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | fastify-reply-from | < 4.0.2 | 4.0.2 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N- Weakness (CWE)
CWE-20- Platform
- npm
- Package
fastify-reply-from- Disclosed
- 03.03.2021
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-qmw8-3v4g-gwj4 - CC BY 4.0
Vulnerability history: fastify-reply-from
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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