TMA-COS-5.1.16
Ensure SSH Idle Timeout Interval is configured
Description
The two options ClientAliveInterval and ClientAliveCountMax control the timeout of ssh sessions. When the ClientAliveInterval variable is set, ssh sessions that have no activity for the specified length of time are terminated. When the ClientAliveCountMax variable is set, sshd will send client alive messages at every ClientAliveInterval interval. When the number of consecutive client alive messages are sent with no response from the client, the ssh session is terminated. For example, if the ClientAliveInterval is set to 15 seconds and the ClientAliveCountMax is set to 3, the client ssh session will be terminated after 45 seconds of idle time. Having no timeout value associated with a connection could allow an unauthorized user access to another user's ssh session (e.g. user walks away from their computer and doesn't lock the screen). Setting a timeout value at least reduces the risk o...
Méthode de vérification
Méthode d'audit: Revue manuelle
Cette recommandation ne peut pas être vérifiée automatiquement. Une analyse la liste avec ces instructions lorsque vous passez --include-manual.
Run the following commands and verify ClientAliveInterval is between 1 and 300 and ClientAliveCountMax is 3 or less: # sshd -T | grep clientaliveinterval ClientAliveInterval 300 # sshd -T | grep clientalivecountmax ClientAliveCountMax 0
Méthode de correction
Méthode de correction: Recommandation ou correctif d'infrastructure
Edit the /etc/ssh/sshd_config file to set the parameters according to site policy: ClientAliveInterval 300 ClientAliveCountMax 0
Propriétés
- Systèmes d'exploitation
- Tous
- Étiquettes
- container-optimized-oscosssh
- Référence
- CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.16 Ensure SSH Idle Timeout Interval is configured