Title

All shell files must have mode 0755 or less permissive. (Cat I impact)

Discussion

Shells with world/group write permissions give the ability to maliciously modify the shell to obtain unauthorized access.

Check Content

Obtain a list of system shells from /etc/security/login.cfg and check the permissions of these shells. Procedure: #grep shells /etc/security/login.cfg | grep -v \* | cut -f 2 -d = | sed s/,/\ /g | xargs -n1 ls -l If any shell has a mode more permissive than 0755, this is a finding. Obtain a list of system shells from /etc/shells and check the ownership of these shells. Procedure: #cat /etc/shells | xargs -n1 ls -l If any shell has a mode more permissive than 0755, this is a finding.

Fix Text

Change the mode of the shell. # chmod 0755 < shell >

Additional Identifiers

Rule ID: SV-38846r1_rule

Vulnerability ID: V-922

Group Title: GEN002220

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.