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.
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.
Deprecation notices have been published for older versions.
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']
});
https://www.npmjs.com/advisories/1445
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
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
{ "nvd_published_at": "2020-08-17T22:15:00Z", "github_reviewed_at": "2020-08-17T21:42:37Z", "severity": "CRITICAL", "github_reviewed": true, "cwe_ids": [ "CWE-918" ] }