DISA STIGS Viewer

AlmaLinux OS 9 must implement nonexecutable data to protect its memory from unauthorized code execution.

Overview

Finding ID Version Rule ID IA Controls Severity
V-269449 ALMA-09-044570 SV-269449r1050620_rule   Medium
Description
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places the memory regions of a process, such as the stack and heap, higher than this address, the hardware prevents execution in that address range.
STIG Date
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide 2025-05-22

Details

Check Text (C-73480r1049725_chk)
Verify ExecShield is enabled on 64-bit AlmaLinux OS 9 systems with the following command:

$ dmesg | grep '[NX|DX]*protection'

[ 0.000000] NX (Execute Disable) protection: active

If "dmesg" does not show "NX (Execute Disable) protection active", this is a finding.
Fix Text (F-73381r1048724_fix)
Update the GRUB 2 bootloader configuration to ensure the noexec kernel parameter is not enabled using the following command:

$ grubby --update-kernel=ALL --remove-args=noexec

Enable the NX bit execute protection in the system BIOS.