Ensure loopback traffic is configured

보통레벨 1자동linux

설명

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network (127.0.0.0/8).

점검 방법

감사 방식: 셸 명령

shell

alt0() { command -v iptables >/dev/null 2>&1 || { echo "step1: iptables not installed"; return 1; }; o=$(bash -c 'iptables -L INPUT -v -n Chain INPUT (policy DROP 0 packets, 0 bytes)' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'pkts bytes target prot opt in out source' || { echo step1: missing 'pkts bytes target prot opt in out source'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- destination || { echo step1: missing destination; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0' || { echo step1: missing '0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '0 0 DROP all -- * * 127.0.0.0/8 0.0.0.0/0' || { echo step1: missing '0 0 DROP all -- * * 127.0.0.0/8 0.0.0.0/0'; return 1; }; command -v iptables >/dev/null 2>&1 || { echo "step2: iptables not installed"; return 1; }; o=$(bash -c 'iptables -L OUTPUT -v -n Chain OUTPUT (policy DROP 0 packets, 0 bytes)' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'pkts bytes target prot opt in out source' || { echo step2: missing 'pkts bytes target prot opt in out source'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- destination || { echo step2: missing destination; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '0 0 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0' || { echo step2: missing '0 0 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0'; return 1; }; }; if alt0; then echo compliant; fi

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

Run the following commands to implement the loopback rules: # iptables -A INPUT -i lo -j ACCEPT # iptables -A OUTPUT -o lo -j ACCEPT # iptables -A INPUT -s 127.0.0.0/8 -j DROP # service iptables save

속성

운영 체제: alinux-2
태그: cis-convertedlinux
참고 자료: CIS Aliyun Linux 2 Benchmark v1.0.0 ARCHIVE - 3.5.1.2

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