The Juniper SRX Services Gateway must implement replay-resistant authentication mechanisms for network access to privileged accounts.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-223216	SRG-APP-000156-NDM-000250	JUSX-DM-000124	SV-223216r960993_rule	2024-12-20	3

Description
A replay attack may enable an unauthorized user to gain access to the application. Authentication sessions between the authenticator and the application 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. There are 2 approved methods for accessing the Juniper SRX which are, in order of preference, the SSH protocol and the console port.

Description

A replay attack may enable an unauthorized user to gain access to the application. Authentication sessions between the authenticator and the application 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. There are 2 approved methods for accessing the Juniper SRX which are, in order of preference, the SSH protocol and the console port.

ℹ️ Check
Verify SSH is configured to use a replay-resistant authentication mechanism. [edit] show system services ssh If SSH is not configured to use the MAC authentication protocol, this is a finding.

✔️ Fix
Configure SSH to use a replay-resistant authentication mechanism. The following is an example stanza. [edit] set system services ssh macs hmac-sha2-512 set system services ssh macs hmac-sha2-256 set system services ssh macs hmac-sha1 set system services ssh macs hmac-sha1-96