Getting Started with the Linux Intrusion Detection System
For MySQL, we need to deny other applications' access to the mysql binary. We also need to restrict access to the mysql/var directory so that it's append=only, and allow read-only access for the mysqld dæmon to the mysql directory:
lidsconf -A -o /usr/local/mysql/var -j APPEND lidsconf -A -o /usr/local/mysql -j DENY lidsconf -A -s /usr/local/mysql/libexec/mysqld -o /usr/local/mysql -j READONLY lidsconf -A -s /usr/local/mysql/libexec/mysqld -o /usr/local/mysql/var -j WRITE
Bind needs a lot of capabilities to run:
lidsconf -A -s /usr/sbin/named -o CAP_NET_BIND_SERVICE 53 -j GRANT lidsconf -A -s /usr/sbin/named -o CAP_SETPCAP -j GRANT lidsconf -A -s /usr/sbin/named -o CAP_SYS_CHROOT -j GRANT lidsconf -A -s /usr/sbin/named -o CAP_SYS_RESOURCE -j GRANT lidsconf -A -s /usr/sbin/named -o CAP_SETUID -j GRANT lidsconf -A -s /usr/sbin/named -o CAP_SETGID -j GRANT
Login is the program that allows a user to log in to a GNU/Linux system:
lidsconf -A -s /bin/login -o /etc/shadow -j READONLY lidsconf -A -s /bin/login -o CAP_SETUID -j GRANT lidsconf -A -s /bin/login -o CAP_SETGID -j GRANT lidsconf -A -s /bin/login -o CAP_CHOWN -j GRANT lidsconf -A -s /bin/login -o CAP_FSETID -j GRANT
After having specified the previous commands, we need to seal the kernel, so that the system can take full advantage of LIDS. We add this line to rc.local:
Restart the machine to apply all the new access controls. With the previously mentioned access controls, you will not be able to run the X server as it uses raw I/O, but most servers don't run an X server anyway. If you really need it, add the following access control (this command assumes that your X server binary is located in /usr/X11R6/bin/startx):
lidsconf -A -s /usr/X11R6/bin/startx
As we can see, LIDS is a powerful addition to the Linux kernel, which can secure your system completely, even from the root user. LIDS is also very easy to use.
Irfan Habib is a software engineering student at the National University of Science and Technology in Pakistan. He has had great interest in Linux and open-source technology since high school—everything from embedded Linux development to Web services. He has been advocating GNU/Linux in Pakistan for the past two years and has written various articles in local magazines and newspapers on the subject.
Fast/Flexible Linux OS Recovery
On Demand Now
In this live one-hour webinar, learn how to enhance your existing backup strategies for complete disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible full-system recovery solution for UNIX and Linux systems.
Join Linux Journal's Shawn Powers and David Huffman, President/CEO, Storix, Inc.
Free to Linux Journal readers.Register Now!
- Firefox 46.0 Released
- Ubuntu Online Summit
- Devuan Beta Release
- The Qt Company's Qt Start-Up
- May 2016 Issue of Linux Journal
- The US Government and Open-Source Software
- The Death of RoboVM
- Download "Linux Management with Red Hat Satellite: Measuring Business Impact and ROI"
- New Container Image Standard Promises More Portable Apps
- Open-Source Project Secretly Funded by CIA
In modern computer systems, privacy and security are mandatory. However, connections from the outside over public networks automatically imply risks. One easily available solution to avoid eavesdroppers’ attempts is SSH. But, its wide adoption during the past 21 years has made it a target for attackers, so hardening your system properly is a must.
Additionally, in highly regulated markets, you must comply with specific operational requirements, proving that you conform to standards and even that you have included new mandatory authentication methods, such as two-factor authentication. In this ebook, I discuss SSH and how to configure and manage it to guarantee that your network is safe, your data is secure and that you comply with relevant regulations.Get the Guide