Linux: Disable ASLR via personality syscall or sysctl/randomize_va_space changes

Flags Linux events where ASLR is disabled using the personality syscall or sysctl setting kernel.randomize_va_space=0.

FreeReviewedSigma · High · v3
Product
linux
Service
auditd
Author
Milad Cheraghi (SigmaHQ), DRL 1.1
Published
2025-05-26
Updated
2026-07-31
title: "Linux: Disable ASLR via personality syscall or sysctl/randomize_va_space changes"
id: 4925c4b1-180f-4fe5-9536-d9719b642f7d
status: experimental
description: This rule identifies Linux activity that disables Address Space Layout Randomization (ASLR) by using the personality syscall with the ADDR_NO_RANDOMIZE flag, modifying /proc/sys/kernel/randomize_va_space, or executing sysctl to set kernel.randomize_va_space=0. Reducing ASLR effectiveness can make memory corruption exploits more reliable and is a common defense-impairment step during adversary tradecraft. It relies on auditd telemetry capturing syscall events for personality and process execution events for sysctl with specific arguments and values.
references:
  - https://github.com/CheraghiMilad/bypass-Neo23x0-auditd-config/blob/f1c478a37911a5447d5ffcd580f22b167bf3df14/personality-syscall/README.md
  - https://man7.org/linux/man-pages/man2/personality.2.html
  - https://manual.cs50.io/2/personality
  - https://linux-audit.com/linux-aslr-and-kernelrandomize_va_space-setting/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/linux/auditd/lnx_auditd_disable_aslr_protection.yml
author: Milad Cheraghi, Huntrule Team
date: 2025-05-26
modified: 2025-12-05
tags:
  - attack.privilege-escalation
  - attack.stealth
  - attack.defense-impairment
  - attack.t1685
  - attack.t1055.009
logsource:
  product: linux
  service: auditd
detection:
  selection_syscall:
    type: SYSCALL
    SYSCALL: personality
    a0: 40000
  selection_sysctl:
    type: EXECVE
    a0: sysctl
    a1: -w
    a2: kernel.randomize_va_space=0
  condition: 1 of selection_*
falsepositives:
  - Debugging or legitimate software testing
level: high
license: DRL-1.1
related:
  - id: e497a24e-9345-4a62-9803-b06d7d7cb132
    type: derived