Cis Ubuntu2004 V300 7 1 10

7.1.10 Ensure access to /etc/security/opasswd is configured (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

/etc/security/opasswd and its backup /etc/security/opasswd.old hold user's previous passwords if pam_unix or pam_pwhistory is in use on the system.

Rationale

It is critical to ensure that /etc/security/opasswd is protected from unauthorized access. Although it is protected by default, the file permissions could be changed either inadvertently or through malicious actions.

Impact

None

Audit Procedure

Command Line

Run the following commands to verify /etc/security/opasswd and /etc/security/opasswd.old are mode 600 or more restrictive, Uid is 0/root and Gid is 0/root if they exist:

# [ -e "/etc/security/opasswd" ] && stat -Lc '%n Access: (%#a/%A) Uid: ( %u/ %U) Gid: ( %g/ %G)' /etc/security/opasswd

/etc/security/opasswd Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)
  -OR-
Nothing is returned

# [ -e "/etc/security/opasswd.old" ] && stat -Lc '%n Access: (%#a/%A) Uid: ( %u/ %U) Gid: ( %g/ %G)' /etc/security/opasswd.old

/etc/security/opasswd.old Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)
  -OR-
Nothing is returned

Expected Result

Mode 600 or more restrictive, Uid 0/root, Gid 0/root for both files (if they exist).

Remediation

Command Line

Run the following commands to remove excess permissions, set owner, and set group on /etc/security/opasswd and /etc/security/opasswd.old if they exist:

# [ -e "/etc/security/opasswd" ] && chmod u-x,go-rwx /etc/security/opasswd
# [ -e "/etc/security/opasswd" ] && chown root:root /etc/security/opasswd
# [ -e "/etc/security/opasswd.old" ] && chmod u-x,go-rwx /etc/security/opasswd.old
# [ -e "/etc/security/opasswd.old" ] && chown root:root /etc/security/opasswd.old

Default Value

/etc/security/opasswd Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)

References

1. NIST SP 800-53 Rev. 5: AC-3, MP-2

CIS Controls

MITRE ATT&CK Mappings: