pynetfilter_conntrack is a Python binding for libnetfilter_conntrack that allows you to manipulate Netfilter's stateful inspection objects. This makes it possible to easily close connections and obtain information about connections such as the number of packets and bytes. It could be used to create conntrack entries, replacing heavy kernel modules for complex protocols such as FTP and H323.
Daemon Shield is a Linux intrusion prevention daemon that scans for brute force break-in attacks in real time and uses iptables to create rules that block the attackers' IP addresses for a configurable period of time. It uses handlers that watch for attacks against given services, such as SSH, telnet, FTP, etc. It is highly configurable through a central configuration file. It loads existing blocklist rules into iptables on startup, and removes the blocklist rules when it shuts down. Other major features include background daemon operation, logging to syslog, easy-to-extend handlers, configurable block duration, and email notifications.
Nuface is a Web-based administration tool that generates Edenwall, NuFW, or simple Netfilter firewall rules. It features a high level abstraction on the security policy set by the administrator, and works internally on an XML data scheme. Its philosophy is to let you agglomerate subjects, resources, or protocols into meta-objects, and use those meta objects to generate ACLs, which are then interpreted as netfilter rules by Nupyf, the internal XML parser. This tool may easily be extended to support firewall implementations other than Netfilter.
Endian Firewall is an all-in-on Linux security distribution that turns any system into a full-featured security appliance. It features a stateful packet inspection firewall, application-level proxies for various protocols (HTTP, POP3, SMTP), anti-virus support, virus and spam filtering for email traffic (POP and SMTP), content filtering of Web traffic, and a "hassle free" VPN system based on OpenVPN.
proxymin is an easy-to-use graphical interface to configure commonly needed Squid ACLs. It allows for fine grained permission management based on users, hosts, and groups. The HTTP, HTTPS, and FTP protocols are currently supported. proxymin has been tested with several hundreds of managed accounts. All major features have been implemented and tested.
Hardened Debian improves Debian GNU/Linux with high security and hardening features, hardened kernels and packages, DHKP, and other security related enhancements. It makes systems more difficult to compromise using common attacks such as race conditions, chroot jail escapes, and buffer overflows.