Securing SSH

I REALLY like secure shell (SSH) for remote access to linux machines. You can do more than just a “telnet” like remote shell with it. (Port forwarding.) However, the default configuraton for the openssh-server is sometimes a bit less tight than I would like. For that reason on a new install, I usually like to make a few changes. I don’t know if I’ve mentioned this before, but I haven’t devoted a post JUST to this, so… here we go.

Under mandriva, the config file for the openssh server is at /etc/ssh/sshd_config First off, I like to make sure that just version 2 of the SSH protocol is used. This may break compatiblity with older clients that don’t support version 2. In a nutshell, v. 2 is a more secure implemenation
, and in my case, I don’t use anything that doesn’t support version 2… so… the following gets changed in the sshd_config – protocol 2,1 is commented out and protocol 2 added.

#Protocol 2,1
Protocol 2

Next, I like to make sure that root login is disabled…

PermitRootLogin no

After all, every system has a root user, why make it a bit easier for someone to brute force their way in?

I also like to setup a group called sshusers and limit access to just those that need to remotely get in.

AllowGroups sshusers

This way if I have a lame test account with an equally lame password, it can’t be remotely exploited this way (unless I’m dumb enough to add them to sshusers…)

The AllowUsers directive is another way to do this…
AllowUsers user1, user2, user3

These are just a couple steps you can take to tighten up your ssh server setup. For more on SSH usage and configuration you might consult the manual (man) pages, or may I suggest SSH, The Secure Shell: The Definitive Guide

Popularity: 1% [?]

Related Posts

Windows 98 and ME in final days of support (6 by my count) July 11th will mark the end of Microsoft's support for Windows 98 and ME. Which means that there will be no further security updates for those systems after that date. In SOME ways, those systems may find comfort in the security through obscurity approach as much malware MAY not run......
How to Remove KeepCop | Keep Cop Removal Guide KeepCop is yet another of those rogue antivirus applications that seem to be such a plague on computer users today. These rogue security applications usually installed without permission, or by means of trickery claiming to be a video codec or flash player update. Further they will start out on your......
Apple Quicktime and OS X updates to patch multiple security vulnerabilities Apple has released Quicktime v. 7.1 for both Windows and OS X to address about 12 vulnerabilities. It looks as though all of the vulnerabilities were related to either a specially crafted images or movies (a variety of formats...) Upgrade or use another viewer... Affected file formats are.... Jpegs, Flashpix,......

Related Websites

Dreamhost Promo Code For 2011 We all know about Dreamhost one of the best web hosting provider in the world, when compared to other low quality hosting providers. Dreamhost is better in terms of features, support, reliability. It is also one of the fastest growing hosting platform which has about 800K+ web sites hosted online.......
Comparison Between Free Of Charge And Paid Web Comparison between free of charge and paid Web security software has turn into a main subject of discussion amongst probably the most of all computer users recently. Numerous people who have employed both free of charge as well as paid Web security software place their strong opinions. Although many people......
John Varvatos – Innovative Rock and Roll Designer with Inspirational Scents Most people have their signature scent. It’s either their first cologne given to them as a birthday present from a high school girlfriend or one that was borrowed from their father when they were young. Change is difficult. Once you find your preferred scent, it’s often scary to leave it......

Computer Tips -Tech Info

Securing SSH

Similar Posts