First of all extremely sorry for not being active as I was busy with some work, Now back to the blogging.
This article will show you how to disable rsyslog rate-limiting, But You can also use rate-limiting according to your requirement.
How to use rate limiting in rsyslog?
This article is tested with rsyslog 5.7.1 on Fedora 13. It will not work with version of rsyslog prior to 5.7.1.
In rsyslog 5.7.1 we introduced rate limiting. This is a option for the Unix Socket Input module called imuxsock. In short, this option limits the amount of messages written into logfiles by a process, if the process tries to write huge amounts of messages in a short period of time.
MySQL Workbench is a unified visual tool for database architects, developers, and DBAs. MySQL Workbench provides data modeling, SQL development, and comprehensive administration tools for server configuration, user administration, backup, and much more. MySQL Workbench is available on Windows, Linux and Mac OS X.
Sharing article which will help you all to Install MySQL Workbench on RHEL 5.4 / CentOS 5.4 x86_64 (64-Bit).
Please follow below steps to install MySQL Workbench on RHEL 5.x / CentOS 6.x 64 Bit version.
The GHOST vulnerability is a serious weakness in the Linux glibc library. It allows attackers to remotely take complete control of the victim system without having any prior knowledge of system credentials. CVE-2015-0235 has been assigned to this issue.
Qualys security researchers discovered this bug and worked closely with Linux distribution vendors. And as a result of that we are releasing this advisory today as a co-ordinated effort, and patches for all distribution are available January 27, 2015.
What is glibc?
The GNU C Library or glibc is an implementation of the standard C library and a core part of the Linux operating system. Without this library a Linux system will not function.
What is the vulnerability?
During a code audit Qualys researchers discovered a buffer overflow in the __nss_hostname_digits_dots() function of glibc. This bug can be triggered both locally and remotely via all the gethostbyname*() functions. Applications have access to the DNS resolver primarily through the gethostbyname*() set of functions. These functions convert a hostname into an IP address.
What is the risk?
There is a remote code execution risk due to this vulnerability. An attacker who exploits this issue can gain complete control of the compromised system.
Is the risk real?
During our testing, we developed a proof-of-concept in which we send a specially created e-mail to a mail server and can get a remote shell to the Linux machine. This bypasses all existing protections (like ASLR, PIE and NX) on both 32-bit and 64-bit systems.
What can be done to mitigate the risk?
The best way to mitigate the risk is to apply a patch from your Linux vendor. Qualys has worked closely with Linux distribution vendors and patches are available as of today January 27, 2015.
Why is it called the GHOST vulnerability?
It is called as the GHOST vulnerability as it can be triggered by the GetHOST functions.
Is this a design flaw?
No. This is an implementation problem in the affected versions of the software.
What versions and operating systems are affected?
The first vulnerable version of the GNU C Library affected by this is glibc-2.2, released on November 10, 2000. We identified a number of factors that mitigate the impact of this bug. In particular, we discovered that it was fixed on May 21, 2013 (between the releases of glibc-2.17 and glibc-2.18). Unfortunately, it was not recognized as a security threat; as a result, most stable and long-term-support distributions were left exposed including Debian 7 (wheezy), Red Hat Enterprise Linux 6 & 7, CentOS 6 & 7, Ubuntu 12.04, for example.
Where can I download the exploit?
We want to give everyone enough time to patch. According to our data once the vulnerability has reached its half-life we will release the exploit. Half-life is the time interval measuring a reduction of a vulnerability’s occurrence by half. Over time, this metric shows how successful efforts have been to eradicate vulnerability. A shorter half-life indicates faster remediation. Half-life was originally coined by Qualys in the Laws of Vulnerability.
Qualys customers can detect GHOST by scanning with the Qualys Vulnerability Management (VM) cloud solution as QID 123191. This means that Qualys customers can get reports detailing their enterprise-wide exposure during their next scanning cycle, which allows them to get visibility into the impact within their organization and efficiently track the remediation progress of this serious vulnerability.
If you are Linux Administrator you must know what SAR is, sar is a very useful utility for Linux Administrators to get the report of CPU Usage and You can monitor I/O, CPU Usage, Idle system state using sar utility. This article will help you to read / export sar reports in Graphical mode.
In this HowTo, I will show you how you can export sar reports as PDF / JPG / PNG using kSar tool.
In RHEL / CentOS you will find sar reports under /var/log/sa
In Ubuntu / Debian based Linux you will find sar reports under /var/log/sysstat
Perform following steps to export sar report:
1. Make Sure Java is installed on your system to open kSar Utility.
If you have not protected Single User Mode with Password then it is big risk for your Linux Server, So protecting Single User Mode with Password is very important when it comes to security,
Today in this article i will show you how you can protect Single User Mode with Password on RHEL / CentOS 5.x and RHEL / CentOS 6.x.
Please execute given commands carefully else your system will not boot properly. First i would request you to read full procedure and then try to follow. Do it at your own risk 🙂
1. For RHEL / CentOS 5.x
1.1 Before doing anything please take backup of your /etc/inittab
cp /etc/inittab /etc/inittab.backup
To Disable and Make Single User Mode Password Protected, Execute below command as root :-
[root@tejas-barot-linux ~]$ sed -i '1i su:S:wait:/sbin/sulogin'
So It will look like below
# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
NOTE: If you do not want to use sedcommand then You can always add “su:S:wait:/sbin/sulogin” at top in /etc/inittab
2. For RHEL / CentOS 6.x
2.1 Before doing anything please take backup of your /etc/inittab
cp /etc/sysconfig/init /etc/sysconfig/init.backup
2.2 To Disable and Make Single User Mode Password Protected, Execute below command as root :-
This how will show you the way to Installing / Upgrading Firefox 17 on RHEL and CentOS 5.x Linux.
In RHEL 5.x and CentOS 5.x there is very Old Firefox version is available, So It is possible that you will not able to use some of the Latest Web based Features from Faebook, Gmail, twitter and LinkedIn.
So To run the Latest Web Based Features, We have to make sure our Firefox version should be Latest and Updated, As of Now there is Firefox 17 is available for the CentOS / RHEL 6.x. We will be Installing / Upgrading the Firefox using YUM.
Please perform following steps to Install Mozilla Firefox on RHEL / CentOS / 5.x :-
Step 1 :- You need to be Root to Install / Upgrade Firefox 17 on RHEL / CentOS / 5.x :-
Step 2 :- Make sure Internet is Direct or You should be able to use Yum for external Repositories from Command Line.
Step 3 :- Close All Firefox Sessions.
Step 4 :- Execute Following Command to Move Existing Repositories to Another Directory to Avoid Package Conflicts.