Junos OS: MX Series: bbe-smgd process crash upon execution of specific CLI commands

A Use After Free vulnerability in command processing of Juniper Networks Junos OS on MX Series allows a local, authenticated attacker to cause the broadband edge service manager daemon (bbe-smgd) to crash upon execution of specific CLI commands, creating a Denial of Service (DoS) condition.  The process crashes and restarts automatically.

When specific CLI commands are executed, the bbe-smgd daemon attempts to write into an area of memory (mgd socket) that was already closed, causing the process to crash.  This process manages and controls the configuration of broadband subscriber sessions and services.  While the process is unavailable, additional subscribers will not be able to connect to the device, causing a temporary Denial of Service condition.

This issue only occurs if Graceful Routing Engine Switchover (GRES) and Subscriber Management are enabled. This issue affects Junos OS:

• All versions before 20.4R3-S5,
• from 21.1 before 21.1R3-S4,
• from 21.2 before 21.2R3-S3,
• from 21.3 before 21.3R3-S5,
• from 21.4 before 21.4R3-S5,
• from 22.1 before 22.1R3,
• from 22.2 before 22.2R3,
• from 22.3 before 22.3R2;