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A pun I cannot resist: the backdoor is in the FTP protocol itself, which is, no matter how secure the deamon serving it is, completely insecure.
by maurycy 15y ago
A pun I cannot resist: the backdoor is in the FTP protocol itself, which is, no matter how secure the deamon serving it is, completely insecure.
- wladimir 15y agoWhat if you only enable FTPS? vsftpd supports that.
- ComputerGuru 15y agovsftpd does, most shared webhosts don't.
- wladimir 15y agoSo, what's your alternative? I guess most shared webhosts don't support ssh either.
- ComputerGuru 15y agoOpenVPN tunnel. That or use a VPS.
- wladimir 15y agoRight. How many shared webhosts support OpenVPN? Yeah, of course you can use a VPS, but then you could have used FTPS-only mode in your own FTP server in the first place... So I guess our conclusion is that most shared webhosts' security is simply crap because they only offer upload via FTP (plain) and HTTP/webdav (plain) and that you should use your own VPS.
- deleted 15y ago[deleted]
- JoachimSchipper 15y agoIf you only care about the integrity of your server FTP is (can be) perfectly fine. If you actually care about people downloading your software, add GPG signatures (note that SSL+certificates doesn't work well if you want to have many mirrors, which is common). Where exactly is the issue?
- maurycy 15y agoIt was a pun. However, let me explain it a bit. The FTP protocol uses plain text. Taking into account that it is most frequently deployed by web hosting companies, that lack of encryption implies a real risk for everyone. It's not a rocket science to launch a network sniffer in an airport, a Starbucks or any other shared network, and capture the FTP credentials of a designer making quick changes to client's ecommerce site. What makes it really bad is that nearly all web apps today include full database credentials, enabling an attacker to either wipe out the data or just copy it. As we have already learned many times, the passwords are rarely stored securely, and users tend to routinely reuse their passwords. A database of any moderately succesful service makes it really easy to get access to hundreds of email, or Facebook, accounts. Of course, this is just an example. There are few other attack vectors relying on that inherent weakness of the FTP protocol. While it is not a backdoor technically, it comes pretty close to it, as it provides an effortless method to gain an unauthorized access. In the past, FTP daemons were buggy and used to run as a root, making them pretty handy to exploit. Now, with privilege separation enabled, it's much better for the administrators but regular users are still at risk. FTP tweaks, like FTP-SSL, are nice in theory but, in practice, they are provided as an option, some FTP clients do not support them, and they do not work well with many standard firewall configurations, due to the secondary data connection port.
- wladimir 15y agodue to the secondary data connection port. Yes, the secondary data connection port is a weakness/annoyance of the FTP protocol, I agree. The other points don't have anything to do with the protocol itself, just with how it is implemented in specific cases.