CVE-2017-5638: Apache Struts 2 Vulnerability

Struts-Shock-Blog

Apache Struts 2 is an open-source development framework for Java applications.
On March 6th, 2017, a vulnerability tracked as CVE-2017-5638 in Apache Struts 2 was made public. This vulnerability could allow an attacker to perform remote code execution with a malicious Content.
This particular vulnerability can be exploited if the attacker sends a  request to upload a file to a vulnerable server that uses a Jakarta-based plugin to process the upload request.
The attacker can then send malicious code in the Content-Type header to execute the command on a vulnerable server.
The Jakarta Multipart parser in Apache Struts 2 2.3.x before 2.3.32 and 2.5.x before 2.5.10.1 mishandles file upload, which allows remote attackers to execute arbitrary commands via a #cmd= string as exploited in the wild in March 2017.

Solution
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Both Cisco and Apache researchers asked administrators to upgrade their systems to Apache Struts version 2.3.32 or 2.5.10.1

Configuration of HAProxy Load Balancer on CentOS

HAProxy stands for High Availability proxy.  It is a very fast and reliable solution for high availability and load balancing. HAProxy is used as TCP/HTTP Load Balancer and for proxy Solutions.The HAProxy application will share the workload with multiple servers.

Steps for Installation and configuring  HAproxy
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Step 1: Before proceeding with the installation of  HAProxy in the server, we need to install epel repository on our system depending on the operating system version using the following command.
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Deploying Openstack using Packstack

OpenStack is a set of software tools for building and managing cloud computing platforms for public and private clouds. Mostly deployed as an infrastructure-as-a-service (IaaS). Deploy virtual machines and other instances that handle different tasks for managing a cloud environment on the fly. It makes horizontal scaling easy, which means that tasks that benefit from running concurrently can easily serve more or fewer users on the fly by just spinning up more instances. So we can say OpenStack is the future of cloud computing.

OpenStack began in 2010 as a joint project of Rackspace Hosting and NASA. As of 2016, it is managed by the OpenStack Foundation, a non-profit corporate entity established in September 2012. Backed by some of the biggest companies in software development and hosting like Intel, Redhat, Cisco, Ubuntu etc, as well as thousands of individual community members.

        Packstack is a utility that uses Puppet modules to deploy various parts of OpenStack on multiple pre-installed servers over SSH automatically. Currently only Fedora, Red Hat Enterprise Linux (RHEL) and Centos are supported. Continue reading…

How to fix Dirty Cow vulnerability – CVE-2016-5195

A serious vulnerability named Dirty COW has been discovered recently which has put the Linux kernel under risk. Its said that this vulnerability was noticed nine years ago (since version 2.6.22 in 2007) and remained unnoticed throughout this time. A researcher named Phil Oester was the man behind the detection of this serious threat.

According to him, the vulnerability is described as a race condition where the Linux kernel’s memory subsystem handles the copy-on-write (COW) breakage of private read-only memory mappings. In this way, the attackers gain write access to read-only memory updates and this paves way to their increased privileges on the system. Continue reading…