TMA-FREEBSD-4.2.11
Ensure sshd KexAlgorithms is configured
Açıklama
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.
Nasıl denetlenir
Denetim yöntemi: Kabuk komutu
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- Beklenen çıktı
compliant
Nasıl düzeltilir
Düzeltme yöntemi: Kılavuz veya altyapı yaması
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
Özellikler
- İşletim sistemleri
- Herhangi biri
- Etiketler
- freebsdssh
- Referans
- CIS FreeBSD 14 Benchmark v1.0.1 - 4.2.11 Ensure sshd KexAlgorithms is configured
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tmaegis scan --target freebsd