An Improper Resource Shutdown or Release vulnerability in the SIP ALG of Juniper Networks Junos OS on MX Series with MS-MPC allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an MX Series device with an MS-MPC is configured with two or more service sets which are both processing SIP calls, a specific sequence of call events will lead to a crash and restart of the MS-MPC. This issue affects Junos OS: all versions before 21.2R3-S9, 21.4 versions from 21.4R1, 22.2 versions before 22.2R3-S6, 22.4 versions before 22.4R3-S6.

As the MS-MPC is EoL after Junos OS 22.4, later versions are not affected. This issue does not affect MX-SPC3 or SRX Series devices.