Security hardening for Debian
Making the programs in a distribution more resistant to exploits—a process known as hardening—is a fairly common way to reduce the attack surface for the distribution. Many distributions have made an effort in this area, with some adding in an overall security architecture, like AppArmor for SUSE or SELinux for Red Hat and Fedora distributions. Debian is currently looking at enabling some hardening features, potentially throughout a large swath of packages that it distributes. The features being considered and the concerns raised provide an interesting look at the tradeoffs.
A posting to debian-devel-announce regarding hardening features for Lenny started the conversation. Those packages that are most susceptible—network services, packages that parse files from untrusted sources, or those that have been the subject of a security alert—should enable a set of security tools that will help deflect attacks against them. Various attacks rely upon certain characteristics of Linux binaries that allow them to be exploited. By altering the way the binaries are built, those particular threats can be mitigated.