Ubuntu 24.04 LTS must implement nonexecutable data to protect its memory from unauthorized code execution.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-270771	SRG-OS-000433-GPOS-00192	UBTU-24-700300	SV-270771r1066802_rule	2025-02-18	1

Description
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. 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.

Description

Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. 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.

ℹ️ Check
Verify the NX (no-execution) bit flag is set on the system with the following command: $ sudo dmesg \| grep -i "execute disable" [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection: active", check the cpuinfo settings with the following command: $ grep flags /proc/cpuinfo \| grep -w nx \| sort -u flags : fpu vme de pse tsc ms nx rdtscp lm constant_tsc If "flags" does not contain the "nx" flag, this is a finding.

ℹ️ Check

Verify the NX (no-execution) bit flag is set on the system with the following command: $ sudo dmesg | grep -i "execute disable" [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection: active", check the cpuinfo settings with the following command: $ grep flags /proc/cpuinfo | grep -w nx | sort -u flags : fpu vme de pse tsc ms nx rdtscp lm constant_tsc If "flags" does not contain the "nx" flag, this is a finding.

✔️ Fix
Configure Ubuntu 24.04 LTS to enable NX. If "nx" is not showing up in "/proc/cpuinfo", and the system's BIOS setup configuration permits toggling the No Execution bit, set it to "enable".