Ensure kernel.yama.ptrace_scope is configured

보통레벨 1자동linux

설명

The ptrace() system call provides a means by which one process (the "tracer") may observe and control the execution of another process (the "tracee"), and examine and change the tracee's memory and registers. The sysctl settings (writable only with CAP_SYS_PTRACE) are: • 0 - classic ptrace permissions: a process can PTRACE_ATTACH to any other process running under the same uid, as long as it is dumpable (i.e. did not transition uids, start privileged, or have called prctl(PR_SET_DUMPABLE...) already). Similarly, PTRACE_TRACEME is unchanged. • 1 - restricted ptrace: a process must have a predef

점검 방법

감사 방식: 셸 명령

shell

chk() { p=$1; allowed=" $2 "; case $p in net.ipv6.*) [ -d /proc/sys/net/ipv6 ] || return 0;; esac; v=$(sysctl -n "$p" 2>/dev/null) || { echo "$p: not available"; return 1; }; case "$allowed" in *" $v "*) ;; *) echo "$p is $v (running)"; return 1;; esac; sd=$(readlink -e /lib/systemd/systemd-sysctl || readlink -e /usr/lib/systemd/systemd-sysctl); f=$("$sd" --cat-config 2>/dev/null | grep -Po "^\h*${p//./\.}\h*=\h*\K\H+" | tail -n1); [ -n "$f" ] || { echo "$p is not set in any sysctl configuration file"; return 1; }; case "$allowed" in *" $f "*) ;; *) echo "$p is $f in configuration"; return 1;; esac; }; if chk kernel.yama.ptrace_scope '1 2 3'; then echo compliant; fi

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

1. Review all files being used by systemd sysctl and comment out or remove all kernel.yama.ptrace_scope lines that are not kernel.yama.ptrace_scope=1, kernel.yama.ptrace_scope=2, or kernel.yama.ptrace_scope=3. Example script: #!/usr/bin/env bash { l_option="kernel.yama.ptrace_scope" l_value="(1|2|3)" l_grep="${l_option//./(\\.|\\/)}" a_files=() l_systemdsysctl="$(readlink -e /lib/systemd/systemd-sysctl \ || readlink -e /usr/lib/systemd/systemd-sysctl)" l_ufw_file="$([ -f /etc/default/ufw ] && \ awk -F= '/^\s*IPT_SYSCTL=/ {print $2}' /etc/default/ufw)" [ -f "$(readlink -e "$l_ufw_file")" ] && \ a_files+=("$l_ufw_file"); a_files+=("/etc/sysctl.conf") while IFS= read -r l_fname; do l_file="$(re…

속성

운영 체제: almalinux-8
태그: cis-convertedkernellinuxsysctl
참고 자료: CIS AlmaLinux OS 8 Benchmark v4.0.0 - 1.5.7

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shell

tmaegis scan --target linux