SYN-flood attack is commonly utilized as a mean to disrupt network communication and it is a form of (Distributed Denial-of-Service) DDOS attack. RFC4987 details common mitigation to deal with SYN-flood attack. However in this post, I’m going to share you the method that I use to reduce the risk of SYN-flood attack from my department […]
Due to the widespread of Litespeed 0-day attack which has affected local websites, it’s imperative for all sysadmin and website operator to patch/update and upgrade the security of the Litespeed web server. This attack is dangerous particularly because the attacker can gain shell access with the same privileges of the web server or the user […]
Although security by obscurity is not the best policy to protect your IS assets, but it is still useful to thwarts simple network scanner or newbie crackers. Note: This tip is written for Ubuntu Linux, the steps is similar to other GNU/Linux distro, albeit with a slight variant. Hiding Apache2 version Edit /etc/apache2/apache2.conf Add these […]
This is the quickest way to limit the number of connection to your SSH server with iptables. [bash] sudo /sbin/iptables -A INPUT -p tcp –syn –dport 22 -m connlimit –connlimit-above 5 -j REJECT [/bash] This will only allow up to 5 concurrent connections to the SSH server, subsequent connections will be rejected by iptables, thus […]
Fail2ban is a security tool used for preventing brute-force attack and Distributed Denial of Service (DDoS) attack to your GNU/Linux box. Fail2ban monitors failed login attempts and subsequently blocks the ip address from further logins. Although Fail2ban can also be used to secure other services in Ubuntu server, in this post, I will only focus […]
OpenID is a standard that allows users to be authenticated in a decentralized manner. OpenID enables user to be identified across the internet using a single unified OpenID identifier (or account). However some websites (particularly blog and forums) insist users to login in order to leave a short comment or remarks which sometimes is not […]