The Juniper EX switch must be configured to implement replay-resistant authentication mechanisms for network access to privileged accounts.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-253903	SRG-APP-000156-NDM-000250	JUEX-NM-000260	SV-253903r960993_rule	2025-03-07	2

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. 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.

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. 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.

ℹ️ Check
Determine if the network device implements replay-resistant authentication mechanisms for network access to privileged accounts. This requirement may be verified by demonstration, configuration review, or validated test results. This requirement may be met through use of a properly configured authentication server if the device is configured to use the authentication server. Verify SSH version 2 is configured for network (remote) access to privileged accounts. [edit system services ssh] protocol-version v2; If the network device does not implement replay-resistant authentication mechanisms for network access to privileged accounts, this is a finding.

ℹ️ Check

Determine if the network device implements replay-resistant authentication mechanisms for network access to privileged accounts. This requirement may be verified by demonstration, configuration review, or validated test results. This requirement may be met through use of a properly configured authentication server if the device is configured to use the authentication server. Verify SSH version 2 is configured for network (remote) access to privileged accounts. [edit system services ssh] protocol-version v2; If the network device does not implement replay-resistant authentication mechanisms for network access to privileged accounts, this is a finding.

✔️ Fix
Configure the network device to implement replay-resistant authentication mechanisms for network access to privileged accounts. set system services ssh protocol-version v2