Solaris Telnet 0-day vulnerability

philos writes "According to SANS ISC, there's a vulnerability in Solaris 10 and 11 telnet that allows anyone to remotely connect as any account, including root, without authentication. Remote access can be gained with nothing more than a telnet client. More information and a Snort signature can be found at riosec.com. Worse, this is almost identical to a bug in AIX and Linux rlogin from way back in 1994."

Comments

Why is this a big deal?

[nettdata]

Who the hell even THINKS about enabling telnet on any box these days?

Re:Why is this a big deal?

[TheGratefulNet]

nothing WRONG with telnet. I use it all the time.

but ONLY on trusted lans, of course.

I find it quicker than ssh logins. of course its quicker, it has no encryption to do. and the initial seeding (at connect time) also takes a LONG time on some boxes (ssh to a cisco box; come back after lunch and you'll get your login prompt).

telnet over a wan is dumb. telnet over a 10' piece of wire is NOT dumb.

telnet has its place.

Re:Why is this a big deal?

[SatanicPuppy]

Telnet is dumb! Quicker than SSH? What the hell? Are you streaming video over your SSH connection or what? Most sane people just use it for a remote console, and speed isn't much of an issue in those circumstances...

Opening/enabling telnet is a mistake. Even if you're using it safely, which, in my mind, is across a hub that isn't connected to anything else but the two computers you're talking to you've still got that port open and vulnerable. Using it on a LAN is just begging someone with a packet sniffer to come along and steal your user info.

Re:Why is this a big deal?

[mi]

If ssh on your cisco boxes is slow, you either have serious network problems [...]

Most likely, the reverse DNS is misconfigured. This is the number one reason for ssh-login delays. Maybe, the nameservers initially put into the router's configuration are no longer reachable due to subsequent "hardening". Or, maybe, they went away and were replaced long ago — without anybody telling the routers. Nothing else on a router uses DNS usually, so this problem affects only ssh-daemon and gets blamed on it...

The daemon could, of course, be a little bit smarter and not try to do a reverse DNS, when there are no hostname-based authorization rules in the first place... But that's a minor bug compared to reverse DNS being dysfunctional.

Re:Why is this a big deal?

[SatanicPuppy]

Sounds like they're more interested in watching their own employees than in securing their systems from external threats.

If it were me I'd just log everything in every session (which is easy), and make the users use SSH. That way you can audit everything they do, every command they type, but still have a level of security. You have to remember that any user can sniff telnet traffic on the network, so forcing everyone to use telnet because you don't trust them means the ones who are untrustworthy have a better chance of stealing something useful from a coworker.

Even better would be to hire trustworthy people and treat them as such in the absence of evidence to the contrary.

Re:Why is this a big deal?

[arth1]

Vendor support for ssh is one factor. Many companies have aversions to installing software unless it's backed by FULL support from the vendor. Having to go to a third party, like F-Secure, to get vendor support is often undesirable, and unfortunately, security can lose to support requirements, service level agreements and response time. Even worse is that there's multiple and sometimes incompatible versions of SSH out there - what may come with one system isn't guaranteed to work with another.
Can you get the OS vendor to jump and have a man there within 30 minutes to fix it if a supported OS function doesn't work? Yes. Can you get the OS vendor to jump and have a man there within 30 minutes if OpenSSH doesn't work? No. Sometimes it's as simple as that, unfortunately.

That said, don't think that I believe telnet is a good substitute for ssh, but often, and especially in a turtled environment (hard on the outside, soft on the inside) where five nines are more important than internal security, it may still be a better choice, at least until all the OS vendors provide fully supported (and compatible!) versions of SSH.

Re:Why is this a big deal?

[bugnuts]

Security best practices are the same whether you're talking about securing your home network or a military network No. It's not. The only thing those have in common is considering what you are protecting, and how much risk you wish to take versus the convenience granted. The specifics are immaterial.

The OP is right, he knows his risks and has deemed it acceptable. You and others, having no idea of the risk, deem it unacceptable and are the ignorant ones.

not an excuse

[otacon]

"Nobody should be using it anyways" is not an excuse. If it is included, it should be held to the same standard as every other application. In some legacy cases I'm sure telnet is of some use. But regardless the fact that it has a practical use or not is irrelevant.

the authors seem very confused ...

[petes_PoV]

First they say there's a bug with telnet passing switches through to login.
Then they start a tirade against sending passwords in the clear.
After that they say the fix is not to use telnet.

Putting aside the holier (more secure) than thou attitudes here about telnet security. I've got to say that not using something because it's broken is never a fix (unless you're a manager). The fix is to mend the problem. In the meantime, maybe, avoid the service. but bear in mind, someone still has to fix it.