SYSLOG: Unexpected Reply
This protocol anomaly triggers when it detects a SYSLOG server reply. The SYSLOG protocol is a one-way protocol (client to the server) and the server should not send replies. This can indicate tunneling over the SYSLOG protocol.
Extended Description
The presence of this packet could indicate a software misconfiguration or that a remote attacker is attempting to tunnel over UDP port 514 to bypass firewall rules.
References
srx-branch-12.3
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-branch-19.4
vsrx-19.4
mx-12.3
mx-19.4
vmx-19.4
mx-19.3
vsrx3bsd-19.4
srx-19.4
vsrx-12.3
vmx-19.3
vsrx-19.2
srx-12.3