Tag Archives: Linux

Samsung becomes Linux Foundation platinum member, takes a seat on board

Excellent!

The Linux Foundation, which was established in 2007, provides a vendor-neutral venue for coordinating the development of the Linux kernel and also employs some key developers, including Linux creator Linus Torvalds. The organization is supported financially by its members, which include individuals and corporations.

via Samsung becomes Linux Foundation platinum member, takes a seat on board | Ars Technica.

Two-factor SSH authentication via Google secures Linux logins

If you use Google Apps and have Linux machines you access via SSH, this is a handy method to add two-factor authentication to your environment:

When Google introduced two-factor authentication for the Google and Google Apps accounts, they also created a pluggable authentication module PAM for Linux. This is great news for people running Linux servers who want to protect their remotely-accessible SSH accounts with two-factor authentication. For free.

via Two-factor SSH authentication via Google secures Linux logins | TechRepublic.

Linux DHCP Client Has Remote Code Execution Flaw

How would you know if someone set up a rogue DHCP server within your network?  Even if it were an accidental deploy of a machine with DHCP service turned on with no intention to exploit this flaw, a rogue DHCP server can cause quite a bit of headache.

The dhclient software does not block commands that contain meta-characters, making it possible for rogue DHCP servers on a targeted network to remotely execute malicious code, the Internet Systems Consortium said on April 5. No known exploits exist in the wild, but it is possible that attackers will now start using the bug to break into networks.

In its advisory, ISC wrote, “dhclient doesn’t strip or escape certain shell meta characters in dhcpd responses.”

The vulnerability exists in versions prior to 3.1-ESV-R1, 4.1-ESV-R2, and 4.2.1-P1, according to the ISC advisory (CVE-2011-0997). Attackers can compromise a DHCP server to send out malicious hostname replies containing shellcode. The dhclient executes the shellcode when processing the hostname replies using its system-level privileges on the client system.

via Linux DHCP Client Has Remote Code Execution Flaw – Security – News & Reviews – eWeek.com.

IE7 on Linux

I recently built an XP virtual machine with IE 6 for a client, perhaps I’ll suggest this as an alternative.  We’ll just need to validate that IE6 on Linux renders web pages identically to a Windows installation.

Ever fancied running Internet Explorer 7 (or even earlier versions) on your Linux machine but didn’t find an easy way of doing it – admit it, wine doesn’t work that smoothly – IEs4Linux is the solution for you, check it out, or the complete guide.

via SecuriTeam Blogs » IE7 on Linux.

Setting the record straight on sudo

I recently read a blog posting that denounced the use of sudo as insecure because of the following (briefly summed up and paraphrased) reasons:

1. The idea that not using the root account is wrong, using root for everything is fine.

2. That using sudo for everything provides a false sense of security over performing an action as root directly

3. That using a user account password to get a root shell is a bad idea

4. That using a root shell is not dangerous, and that this “grave misunderstanding” came from the idea that running X as root is dangerous

5. That sudo has very little place in the Enterprise

6. That relying on sudo is foolish, because it has bugs

7. That everything should be done from a root shell, and that you should have to know the “uber-secret root password” to get that access

My first reaction to this blog posting was that the author had no idea how to use sudo properly or why you would want to. My second reaction was to give a big thank you to Ubuntu and OS X that, by default, provide a password-less root account and give administrators sudo access to everything, which pretty much leads to these kinds of silly anti-sudo articles.

via Setting the record straight on sudo | Linux and Open Source | TechRepublic.com.

Vincent Danen actually does a good job countering those assertions, and gives examples on how to properly use sudo.  Read the comments also – I learned “sudo -s,” which I hadn’t used before.

New way to stop or start gdm/X server in Ubuntu Karmic 9.10 using service command

Coincidentally, this morning I was doing the exact same thing as this fellow.  I had installed 9.10 on a Dell GX620 with an nVidia 6600, and needed to stop X in order to compile and install the driver.

I had already downloaded the Linux installable from nVidia, and found this excellent tip for getting in and out of the GUI:

To stop gdm from virtual console (after going to virtual console by giving Ctrl + Alt + F1):

sudo service gdm stop

To start after installing nvidia drivers or whatever we did in console, to start it is as simple as stopping

sudo service gdm start

via My experiments with Linux: New way to stop or start gdm/X server in Ubuntu Karmic 9.10 using service command.

<ctrl-alt-f1> drops you to a console login, but gdm and X are still running in the background, and nVidia drivers will not load until gdm is stopped.

Restarting gdm will bring you back into your Gnome X session.  Alternatively, if you were just doing some work at the console and want to return to your X session without restarting gdm (which closes all your windows and programs, etc), just press <ctrl-alt-f7> to return from the console.