Server-Side Request Forgery in ftp-srv
Background
The FTP protocol creates two connections, one for commands and one for transferring data. This second data connection can be created in two ways, on the server by sending the PASV command, or on the client by sending the PORT command.
The PORT command sends the IP and port for the server to connect to the client with.
Issue
Since the client can send an arbitrary IP with the PORT command, this can be used to cause the server to make a connection elsewhere.
Patches
- fix: disallow PORT connections to alternate hosts: e449e75219d918c400dec65b4b0759f60476abca
Deprecation notices have been published for older versions.
Workarounds
Blacklisting the FTP Command PORT will prevent the server from exposing this behaviour through active connections until a fix is applied.
const ftp = new FtpSrv({
blacklist: ['PORT']
});References
https://www.npmjs.com/advisories/1445
Credits
Thank you to; @trs for fixing it @andreeleuterio for reporting it to us for an anonymous user (Vincent) through the NPM platform @quiquelhappy for bringing it to our attention after it slipped through the cracks during Christmas
For more information
If you have any questions or comments about this advisory:
- Open an issue at https://github.com/autovance/ftp-srv
- Email us directly; security@autovance.com
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | ftp-srv | >= 1.0.0, < 2.19.6, >= 3.0.0, < 3.1.2, >= 4.0.0, < 4.3.4 | 2.19.6, 3.1.2, 4.3.4 |
References
- https://github.com/autovance/ftp-srv/security/advisories/GHSA-jw37-5gqr-cf9j
- https://nvd.nist.gov/vuln/detail/CVE-2020-15152
- https://github.com/autovance/ftp-srv/commit/5508c2346cf23b24c20070ff2e8a47c647d3d5b5
- https://github.com/autovance/ftp-srv/commit/e449e75219d918c400dec65b4b0759f60476abca
- https://github.com/autovance/ftp-srv/commit/fb32b012c3baf48ee804e1dc36544cbba70b00d3
- https://www.npmjs.com/advisories/1445
- https://www.npmjs.com/package/ftp-srv
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- Weakness (CWE)
CWE-918- Platform
- npm
- Package
ftp-srv- Disclosed
- 17.08.2020
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-jw37-5gqr-cf9j - CC BY 4.0
Vulnerability history: ftp-srv
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 08.2020 02.2021
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 1
- Medium 1
Disclosures per year
- 2020: 2
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 0
-
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