7 articles Linux Security

Pluggable Authentication Module (PAM)

Please note these notes are based on CentOS/RHEL 5 – What is PAM ? The glue between authentication methods [eg one-time pwds, kerberos, smart cards] and applications requiring authentication services [eg. ftpd, sshd, imapd] etc It is another layer on 1st-Level defense in Linux. – The 4 directories we are concerned with: /lib/libpam*      [3 files…

Preventing Brute Force Attacks with Fail2Ban

If you have FTP or SSH server exposed to internet with static IP, then you may face issue of Brute Force Attack on your FTP or SSH server. In this article, we will learn how to secure our FTP or SSH server from Brute Force Attack

Making a Linux box as Simple router and Firewall

 Scenario:1 One Linux Box as a firewall having 2 Lan cards or 1 lan card and one internet modem connection.2. eth0 –> Connected to Broadband. IP is 192.168.1.2  in case of dialup it can be “ppp0”3. eth1 –> Connected to Local LAN IP is 192.168.2.1Note: In case of broadband your default gateway should be IP…

Disable SSL ciphers below 128-bit in IBM Apache

For Allowing 128 bit browsers access, while denying lower strength browsers (40 bit, 56 bit) from connecting to the Web server over SSL, we need to use SSLCipherSpec directives within the SSL VirtualHost stanza located in the httpd.conf file.