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Insecure service configuration - SSH

Description

The SSH service is not filtered by the Firewall to avoid external attacks and possible intrusions through this service.

Impact

Attempt to access the server through brute force attacks or 0-day exploits.

Recommendation

Securely configure the vulnerable service so that it can only be accessed by authorized users.

Threat

External attacker without credentials.

Expected Remediation Time

⌚ 60 minutes.

Score

Default score using CVSS 3.1. It may change depending on the context of the src.

Base

  • Attack vector: N
  • Attack complexity: L
  • Privileges required: N
  • User interaction: N
  • Scope: U
  • Confidentiality: L
  • Integrity: N
  • Availability: N

Temporal

  • Exploit code madurity: X
  • Remediation level: O
  • Report confidence: X

Result

  • Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:X/RL:O/RC:X
  • Score:
    • Base: 5.3
    • Temporal: 5.1
  • Severity:
    • Base: Medium
    • Temporal: Medium

Score 4.0

Default score using CVSS 4.0 . It may change depending on the context of the src.

Base 4.0

  • Attack vector: N
  • Attack complexity: L
  • Attack Requirements: N
  • Privileges required: N
  • User interaction: N
  • Confidentiality (VC): L
  • Integrity (VI): N
  • Availability (VA): N
  • Confidentiality (SC): N
  • Integrity (SI): N
  • Availability (SA): N

Threat 4.0

  • Exploit madurity: X

Result 4.0

  • Vector string: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X
  • Score:
    • CVSS-BT: 6.9
  • Severity:
    • CVSS-BT: Medium

Compliant code

The service only allows safe access to certain users

name: "myhost""
AddressFamily: any
AllowAgentForwarding: false
AllowTcpForwarding: true
ListenAddress: {{ ansible_default_ipv4.address }}:{{ ssh_port | default('22') }}
PubkeyAuthentication: true
//Firewall configuration
hosts: myhost.com
vars:
ansible_port: "{{ ssh_port | default('22') }}"
remote_user: sven
become: true
roles:
- hostnames
- users
- ssh
- my.firewall
firewall_allowed_tcp_ports:
- 80
- 443
- 5930

Non compliant code

There is a resource with an SSH configuration allowing any address

name: "myhost""
AddressFamily: any
AllowTcpForwarding: true
ListenAddress: any

Requirements

Fixes

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