Title

AIX must use the SSH server to implement replay-resistant authentication mechanisms for network access to privileged and non-privileged accounts. (Cat I impact)

Discussion

A replay attack may enable an unauthorized user to gain access to the operating system. Authentication sessions between the authenticator and the operating system validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. A privileged account is any information system account with authorizations of a privileged user. Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. Satisfies: SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058

Check Content

Run the following command to check if SSH server package is installed: # lslpp -i |grep -i ssh openssh.base.server 6.0.0.6201 If package "openssh.base.server" is not installed, this is a finding. Run the following command to check if SSH daemon is running: # lssrc -s sshd The above command should yield the following output: Subsystem Group PID Status sshd ssh 4325532 active If the "Status" is not "active", this is a finding.

Fix Text

If the SSH server package is not installed, install "openssh.base.server" package from AIX DVD Volume 1 using the following command (assuming that the DVD device is /dev/cd0): # installp -aXYgd /dev/cd0 -e /tmp/install.log openssh.base.server After the installation, set up the SSH server accordingly. If the SSH daemon is not running, run the following command to start it: # startsrc -s sshd

Additional Identifiers

Rule ID: SV-215179r853452_rule

Vulnerability ID: V-215179

Group Title: SRG-OS-000112-GPOS-00057

Expert Comments

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