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March 2024
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Boot Partition Full ( CentOS 7 )

Boot Partition Full ( CentOS 7 )

root@RHEL7HARDEN:~# df -h

Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg0-root 96G 15G 77G 16% / devtmpfs 3.8G 0 3.8G 0% /dev tmpfs 3.8G 152K 3.8G 1% /dev/shm tmpfs 3.8G 9.1M 3.8G 1% /run tmpfs 3.8G 0 3.8G 0% /sys/fs/cgroup /dev/sda1 283M 270M 0 100% /boot /dev/mapper/vg0-home 577G […]

Verify Package Integrity Using RPM

Verify Package Integrity Using RPM

The RPM package management system includes the ability to verify the integrity of installed packages by comparing the installed files with information about the files taken from the package metadata stored in the RPM database.

Although an attacker could corrupt the RPM database (analogous to attacking the AIDE database […]

Remount the /dev/shm Partition in Fedora/CentOS

Remount the /dev/shm Partition in Fedora/CentOS This is to assist with a CSF warning you may receive about /dev/shm being incorrectly mounted, simply run the following:

nano /etc/fstab

Replace this line:

tmpfs /dev/shm tmpfs defaults 0 0

With this one:

tmpfs /dev/shm tmpfs defaults,noexec,nosuid 0 0

Save & Exit nano, then remount using the following […]

Bloging on Open Source,Linux,BSD and Internet World What is /dev/shm and how to mount /dev/shm

What is /dev/shm and how to mount /dev/shm

Introduction: /dev/shm is nothing but implementation of traditional shared memory concept. It is an efficient means of passing data between programs. One program will create a memory portion, which other processes (if permitted) can access. This will result into speeding up things on Linux. shm / shmfs […]

mount s3 bucket in linux EC2 instance

if you have not created a s3 bucket kindly go through with EC2 documentation.The documentation is very clear and easy to understand .This is the link how to create S3bucket

After creating a new bucket follow the given below steps.

Step 1: Download the latest s3fs package from S3fs link

http://s3fs.googlecode.com/files/s3fs-1.63.tar.gz

Step 2: Untar the […]

Increasing Linux server security with nodev, nosuid and no exec options

Expertise level: Advanced Hackers can use temporary storage directories such as /tmp to store and execute unwanted programs and hack into a server. Other temporary storage directories that can be used for malicious activities are /var/tmp and /dev/shm. Follow these steps to secure your Linux server against this vulnerability: Add nodev, nosuid, and noexec options […]

Remove The GNOME GUI on RHEL 7 Centos 7 Fedora and Oracle Linux Server

[root@RHEL7HARDEN ~]# rpm -qa yum yum-3.4.3-132.el7.centos.0.1.noarch [root@RHEL7HARDEN ~]#

 

I captured the list of ‘Warning: group <groupname> does not exitst.’ (see previous post) from a ‘yum update’ run which I CTRL+c out of once the warnings ended. I removed the ‘Warning: group ‘ from the front and the ‘ does not exitst.’ from the back […]

Remove Old Kernels on RHEL, CentOS, Fedora

Remove Old Kernels on RHEL, CentOS, Fedora This is quick guide howto delete/remove/clean old kernels on Fedora, CentOS, Red Hat (RHEL). I use here two kernel as example, if you want to keep other more or less, then adjust amount of installed kernels as you wish. Normally reason why you maybe want remove kernels is […]

xmlrpc.php attack on WordPress – High CPU usage

xmlrpc.php attack on WordPress – High CPU usage

Just noticed that incoming emails were being delayed by about 30 minutes, we host our emails on Google Apps, so that couldn’t have been the issue. Next step was to investigate the server where the DNS of our domain was being hosted. Turns out the server was […]

Disable / Hide PHP Notices & Warnings – Server wide

Disable / Hide PHP Notices & Warnings – Server wide

A client’s website was continuously getting PHP Notices regarding PHP session clean up issues. The solution turned out to be more complicated than initially thought, sessions need to be moved into RAM.

A quick solution for this is to disable PHP from displaying Notices

error_reporting […]