file-idle-timeout-interval: Set SSH Idle Timeout Interval

2025-08-01 file-idle-timeout-interval PoC Public

Description

Missing an SSH idle timeout interval can lead to security risks by allowing unattended sessions to remain open, increasing the chance of unauthorized access or session hijacking.

PoC

id: file-idle-timeout-interval

info:
  name: Set SSH Idle Timeout Interval
  author: pussycat0x
  severity: unknown
  description: |
    Missing an SSH idle timeout interval can lead to security risks by allowing unattended sessions to remain open, increasing the chance of unauthorized access or session hijacking.
  remediation: |
    Set ClientAliveInterval 300 and ClientAliveCountMax 0 in /etc/ssh/sshd_config to enforce an idle timeout and restart the SSH service.
  reference:
    - https://vishalraj82.medium.com/hardening-openssh-security-37f5d634015f
    - https://support.forcepoint.com/s/article/000015900
  metadata:
    verified: true
  tags: audit,config,file,ssh

file:
  - extensions:
      - all

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "# This is the sshd server system-wide configuration file"

      - type: word
        words:
          - "ClientAliveInterval"
          - "ClientAliveCountMax"
        condition: or
        negative: true
# digest: 4a0a00473045022015133b4487142ff83a65980780210a8b78377c08d5939d117b528ec49b78f98b022100d2edb3ca543c655c9bd84f3888309b4a20c40557074dd405bcea1df996c843a2:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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