Modern Linux distributions offer some mitigation techniques to make it harder
to exploit software vulnerabilities reliably. Mitigations such as RELRO,
NoExecute (NX), Stack Canaries, Address Space Layout Randomization (ASLR) and
Position Independent Executables (PIE) have made reliably exploiting any
vulnerabilities that do exist far more challenging. The checksec script is
designed to test what *standard* Linux OS and PaX (http://pax.grsecurity.net/)
security features are being used.
As of version 1.3 the script also lists the status of various Linux kernel
checksec can check binary-files and running processes for hardening features.