DISA STIGS Viewer

AlmaLinux OS 9 must restrict usage of ptrace to descendant processes.

Overview

Finding ID Version Rule ID IA Controls Severity
V-269424 ALMA-09-040940 SV-269424r1050307_rule   Medium
Description
Unrestricted usage of ptrace allows compromised binaries to run ptrace on other processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g. SSH sessions, web browser etc.) without any additional assistance from the user (i.e. without resorting to phishing).
STIG Date
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide 2025-05-22

Details

Check Text (C-73455r1049682_chk)
Verify AlmaLinux OS 9 restricts usage of ptrace to descendant processes (1), admins only (2), or disables ptrace entirely (3) with the following command:

$ sysctl kernel.yama.ptrace_scope

kernel.yama.ptrace_scope = 1

If the returned line has a value of "0" or a line is not returned, this is a finding.

Check that the configuration files are present to enable this kernel parameter.

$ /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.yama.ptrace_scope | tail -1

kernel.yama.ptrace_scope = 1

If "kernel.yama.ptrace_scope" is equal to "0" or nothing is returned, this is a finding.
Fix Text (F-73356r1049683_fix)
Configure AlmaLinux OS 9 to restrict usage of ptrace to with the following command:

$ echo "kernel.yama.ptrace_scope = 1" > /etc/sysctl.d/60-ptrace.conf

Load settings from all system configuration files with the following command:

$ sysctl --system