UBTU-22-213020 Ubuntu 22.04 LTS must implement address space layout randomization to protect its memory from unauthorized code execution.
All changes in this version
Maps to SI-16 via CCI-002824
Title
Ubuntu 22.04 LTS must implement address space layout randomization to protect its memory from unauthorized code execution.
Control
Verify Ubuntu 22.04 LTS implements address space layout randomization (ASLR) by using the following command: $ sysctl kernel.randomize_va_space kernel.randomize_va_space = 2 If no output is returned, verify the kernel parameter "randomize_va_space" is set to "2" by using the following command: $ cat /proc/sys/kernel/randomize_va_space 2 If "kernel.randomize_va_space" is not set to "2", this is a finding. Verify that a saved value of the "kernel.randomize_va_space" variable is not defined. $ sudo grep -ER "^kernel.randomize_va_space=[^2]" /etc/sysctl.conf /etc/sysctl.d If this returns a result, this is a finding.
Discussion
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in prohibited memory locations. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks.
Related controls
CCI-002824
Fix
Remove the "kernel.randomize_va_space" entry found in the "/etc/sysctl.conf" file or any file located in the "/etc/sysctl.d/" directory. Reload the system configuration files for the changes to take effect by using the following command: $ sudo sysctl --system