Advisories and Patches
Debian Bug Tracking System, Debian Security Information, Linux Security Patches, Red Hat Errata
Articles
A Bit About Security, Adding Security to Common Linux Distributions, Creating a Linux Firewall, Linux Kernel 2.4 Firewalling Matures: netfilter, Linux Security 101, More Linux Security, Next Generation Kernel Security, Replacing Telnet: OpenSSH, a secure alternative, Securing Linux, Part 1, Securing Your Linux Box
Distributions
Astaro Internet Security, Castle, Devil-Linux, EnGarde, HP Secure OS Software for Linux, JBLinux, Migrating to Astaro Security Linux, Owl, Project Plan-B, Security Enhanced Linux
Documentation
A Short History of Cryptography, A Simple Scheme to Make Passwords Based on One-Way, Firewall Piercing mini-HOWTO, Firewalling and Proxy Server HOWTO, Installing a firewall, Part 1, Introduction to Linux Networking and Security, Linux Administrator's Security Guide, Linux Bridge+Firewall Mini-HOWTO, Linux Firewall Howto, Linux IPCHAINS-HOWTO
Kernel
Flask: An Operating System Security Architecture, Linux Security Module, Linux Security Protection System (LinSec), Medusa DS9 Security System, Rule Set Based Access Control (RSBAC) for Linux, Security ACLs for Linux kernel, Security patch for Linux kernel 2.4, Stik's Security Module, The Linux Encryption HOWTO Homepage
Bastille Linux
Attempts to "harden" (tighten the configuration of) a Red Hat or Mandrake Linux installation.
Dranch: TrinityOS
Step by step, example driven, HOWTO on building a Linux box with an aim towards strong security. Also, links to resources and mailing lists.
Exploit World - Linux Section
Known vulnerabilities on the Linux system with detailed description.
Googgun Technologies Praetor module
Praetor is a kernel-based "Security Enabler" for Linux that provides fine-grained access control.
Hacking Linux Exposed
Companion Website to Hacking Linux Exposed, Osborne/McGraw-Hill. Source code from the book, updates, and other tools to secure your Linux system.
Linux Audit and Intrusion Detection
InterSect Alliance are the creators of the SNARE Linux C2-style Audit module, and have a consulting background in advanced audit analysis, intrusion detection systems, and forensics for Unix and other operating systems.
Linux Security
Information collected from many sources: feature articles, advisories, news, documentation, forums, links.
Linux Security
Linux Security, server hardening, 1U server, 24x7 server admin, monitoring, IDS, NDS, firewalls
Linuxbroker - Security
Linuxbroker provides all types of resources you need like Linux newsgroups search engine, daily news, howtos, applications releases tracking and security alerts.
LinuxSecure
This site on Linux and security covers firewalls (iptables), intrusion detection systems (snort), securing services, and Linux security in general. The aim is to provide information about protection, detection, and reaction with respect to attacks.
New Security Features in Linux 2.4
Selective privileges (capabilities), cryptography, random number devices.
NiftyBox Advisor
Open-source security tools including "Advisor" to automatically notify an admin when a security advisory affects an installed package.
Password Management System
Designed for System Administrators, to handle user logins for several computers running Linux. It works with a console interface, based on the CDK library that uses ncurses. Import data from csv files and export to text files with a free definable format.
Penetrator Megablaster
A kernel module that detects and stops overflow attacks, like Linux Buffer Overflow attack security, which aim to get an interactive access to the system.
Sardonix.org
DARPA-funded community project to audit the source of all Linux applications for security vulnerabilities.
SSH, the Secure Shell: The Definitive Guide
This is a companion website for "SSH: The Secure Shell The Definitive Guide" by Daniel Barrett and Richard Silverman (O'Reilly, 2003). It contains technical details on the SSH as well as sample book material.
StegFS - A Steganographic File System for Linux
Not only does it encrypt data, it also hides it such that it cannot be proved to be there.
The Digital Underground
Computer and Technology articles, and a members page for the "digital underground" community with text, programs, and security information.
The Linux Kernel Auditing Project
The project that aims to audit the Linux kernel for security vulnerabilities and other bugs.
Virtual eXecuting Environment for Linux
Open Source virtual-machine-type security system for Linux servers.