Details
Address space layout randomization (ASLR) is an exploit mitigation technique which randomly arranges the address space of key data areas of a process.
Rationale:
Randomly placing virtual memory regions will make it difficult to write memory page exploits as the memory placement will be consistently shifting.
Solution
Set the following parameter in /etc/sysctl.conf or a /etc/sysctl.d/* file:
kernel.randomize_va_space = 2
Run the following commands to comment out entries that override the default setting of kernel.randomize_va_space:
# sed -ri ‘s/^s*kernel.randomize_va_spaces*=s*([0-1]|[3-9]|[1-9][0-9]+)/# &/gi’ /etc/sysctl.conf
# [ -e /etc/sysctl.d/* ] && sed -ri ‘s/^s*kernel.randomize_va_spaces*=s*([0-1]|[3-9]|[1-9][0-9]+)/# &/gi’ /etc/sysctl.d/*
Run the following command to set the active kernel parameter:
# sysctl -w kernel.randomize_va_space=2
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection, System and Information Integrity.This control applies to the following type of system Unix.