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A Textbook Buffer Overflow: A Look at the FreeBSD telnetd Code
- bdr 15y agoOk, but no one uses telnetd, right?
- langsamer 15y agoThat is probably why it was overlooked
- draven 15y agoI've seen it being used by oldschool (obsolete) admins. When asked about security they argue the servers are in a DMZ, so it's safe, right?
- ars 15y agoThese days telnet comes wrapped in SSL, so it's totally possible to use it securely. I prefer public keys and almost never use telnet, but SSL telnet should be just as secure as password SSH.
- yason 15y agoWhat's the point of SSL telnetd, because one could just use ssh? You still have to bring in some heavy crypto libraries (openssl) so 'telnets' isn't any more lightweight solution either. The only reason I can think of is some corporate policy that dictates the use of telnet, and for some reason SSL is approved but ssh, that hacking tool, isn't.
- deleted 15y ago[deleted]
- sigil 15y agoMaybe because of the PKI features of SSL? For instance...with an SSH client, the first time you contact a new server you're asked to verify the remote host's identity. I bet most of us just blindly type 'y' at this point despite the security implications. On the other hand, with SSL, you can have the server cert signed by a CA the client trusts.
- packetslave 15y agoOpenSSH supports PKI-based authentication and server certificate signing as of 5.4. Very useful in big enterprises and higher-security environment. http://blog.habets.pp.se/2011/07/OpenSSH-certificates http://blog.habets.pp.se/2011/07/OpenSSH-certificates
- sigil 15y agoVery cool, thanks for the info.
- deleted 15y ago[deleted]
- ars 15y agoSSL telnet was created (May 2004) when SSH was not particularly popular yet.
- yason 15y agoSSH was actively replacing telnet in the late 90's already in any decent institution. At universities it was pretty much the standard. (At least on my side of the globe.)
- KonradKlause 15y ago> Ok, but no one uses telnetd, right? No. Telnet is heavily used in industrial environments.
- makmanalp 15y agoThis makes me so scared.
- pjscott 15y agoHopefully they have the intelligence to firewall it off, and only allow LAN use of telnet. Hopefully.
- harshreality 15y agoThere are also a fair number of soho [wireless] routers with telnet enabled by default. I guess that's partly due to memory footprint, or assumed memory footprint (dropbear being fairly small), by the manufacturers, and partly due to windows not having a ssh client by default, whereas every major OS comes with a telnet client.
- Dylan16807 15y agoKeep in mind that for some reason they default-disabled the telnet client on Vista and later.
- cperciva 15y agoDebian popcon says they have 371 people using it regularly.
- demetris 15y agoFor those who don’t know, “popcon” is short for Debian Popularity Contest, a project that collects stats about the usage of Debian packages from users who have installed the optional popcon package. http://popcon.debian.org/ http://popcon.debian.org/
- deleted 15y ago[deleted]
- thirsteh 15y agohttps://twitter.com/#!/cperciva/status/150864360170983424 https://twitter.com/#!/cperciva/status/150864360170983424
- enjoy-your-stay 15y agoI hereby propose a change to memcpy to include a maxbytes parameter and an optional assert() if len exceeds it. Might turn up a few interesting things.
- subleq 15y agomemcpy's third argument is the maximum (additionally, the exact) number of bytes it will copy.
- hackermom 15y agoHow many hands are needed to count the people still using telnet for anything remotely? I can see embedded use in isolated LANs, but...
- ams6110 15y agoAnyone know if the other BSDs share this code?
- Nick_C 15y agoAccording to comments on Colin's message, all BSDs as the bug has been there for years. OpenBSD doesn't have telnetd in its base distribution (and I currently don't have access to my OpenBSD server to check on the ports).