Rule Set Based Access Control (RSBAC) is a Free Software security extension for current Linux kernels. It is based on the Generalized Framework for Access Control (GFAC) by Abrams and LaPadula and provides a flexible system of access control based on several modules. All security relevant system calls are extended by security enforcement code. This code calls the central decision component, which in turn calls all active decision modules and generates a combined decision. This decision is then enforced by the system call extensions.
runsuid runs a script with another user-id/group-id, when the user has the right to do so according to the configuration file. If used in the right combination with access restrictions this can ease the life of system administrators. Additionally, it can be used for running CGI-scripts as different fixed users.
Saint Jude is a wholly kernel-based intrusion detection and intrusion response system that implements the Saint Jude Model for detection of improper privilege transitions. Saint Jude can detect the presence of ongoing and successful attacks, from sources both local and remote, that would yield root-level access to the attacking individual. Detection is performed using a rule-based anomaly detector that uses a model of normal system behavior that is generated on the protected machine during a training phase. By comparing actual actions against a fully developed model, it is possible to detect attacks against vulnerabilities that are both known and unknown with no false positives or negatives.
samhain is a daemon that can check file integrity, search the file tree for SUID files, and detect kernel module rootkits (Linux only). It can be used either standalone or as a client/server system for centralized monitoring, with strong (192-bit AES) encryption for client/server connections and the option to store databases and configuration files on the server. For tamper resistance, it supports signed database/configuration files and signed reports/audit logs. It has been tested on Linux, FreeBSD, Solaris, AIX, HP-UX, and Unixware.
Seahorse is a Gnome front end for GnuPG, the GNU Privacy Guard program. It is a tool for secure communications and data storage. Data encryption and digital signature creation can easily be performed through a GUI and Key Management operations can easily be carried out through an intuitive interface.