Ensure sshd KexAlgorithms is configured

CaoCấp 1Tự độngfreebsd

Mô tả

Key exchange is any cryptography method that exchanges cryptographic keys between two parties, allowing the use of a cryptographic algorithm. If the sender and receiver wish to exchange encrypted messages, each must be equipped to encrypt messages to be sent and decrypt messages received. Key exchange methods that are considered weak should be removed. A key exchange method may be weak because too few bits are used or the hashing algorithm is considered too weak. Using weak algorithms could expose connections to man-in-the- middle attacks. Audit: the effective `kexalgorithms` list from `sshd -T` must not contain any weak algorithm listed by CIS.

Cách kiểm tra

Phương pháp kiểm tra: Lệnh shell

shell

command -v sshd >/dev/null 2>&1 || exit 1; out=$(sshd -T 2>/dev/null) || exit 1; line=$(printf '%s\n' "$out" | grep -i '^kexalgorithms '); [ -n "$line" ] || exit 1; printf '%s\n' "$line" | grep -Eiq -- '(^|[ ,])(diffie-hellman-group1-sha1|diffie-hellman-group14-sha1|diffie-hellman-group-exchange-sha1)(,|$)' && echo "weak: $line" || echo compliant

Đầu ra mong đợi: compliant

Cách khắc phục

Phương pháp khắc phục: Hướng dẫn hoặc bản vá hạ tầng

Edit the /etc/ssh/sshd_config file and add/modify the KexAlgorithms line to contain a comma-separated list of the site unapproved (weak) KexAlgorithms preceded with a - above any Include entries: Example: KexAlgorithms -diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie- hellman-group-exchange-sha1

Thuộc tính

Hệ điều hành: Bất kỳ
Thẻ: freebsdssh
Tham chiếu: CIS FreeBSD 14 Benchmark v1.0.1 - 4.2.11 Ensure sshd KexAlgorithms is configured

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shell

tmaegis scan --target freebsd