An Unchecked Error Condition vulnerability in the subscriber management daemon (smgd) of Juniper Networks Junos OS allows an unauthenticated adjacent attacker to cause a crash of and thereby a Denial of Service (DoS).

In a subscriber management / broadband edge environment if a single session group configuration contains dual-stack and a pp0 interface, smgd will crash and restart every time a PPPoE client sends a specific message.

This issue affects Juniper Networks Junos OS on MX Series:

16.1 version 16.1R1 and later versions prior to 18.4R3-S10;

19.1 versions prior to 19.1R2-S3, 19.1R3-S7;

19.2 versions prior to 19.2R1-S8, 19.2R3-S4;

19.3 versions prior to 19.3R3-S4;

19.4 versions prior to 19.4R3-S5;

20.1 versions prior to 20.1R3-S3;

20.2 versions prior to 20.2R3-S3;

20.3 versions prior to 20.3R3-S2;

20.4 versions prior to 20.4R3;

21.1 versions prior to 21.1R3;

21.2 versions prior to 21.2R2.

This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.

The following is an example of an affected configuration:

user@device# show system services dhcp-local-server dhcpv6
...
group <group-name1> {
   overrides {
      ...
      dual-stack <dual-stack-group-name> ;
   }
   ...
   interface pp0.0;
   ...
}

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned  CVE-2022-22160 .

The following software releases have been updated to resolve this specific issue: 18.4R3-S10, 19.1R2-S3, 19.1R3-S7, 19.2R1-S8, 19.2R3-S4, 19.3R3-S4, 19.4R3-S5, 20.1R3-S3, 20.2R3-S3, 20.3R3-S2, 20.4R3, 21.1R3, 21.2R2, 21.3R1, and all subsequent releases.

This issue is being tracked as  1580528 .

Remove the pp0 interface from a DHCPv6 dual-stack group and move to its own group with no dual-stack enabled.

user@device# show system services dhcp-local-server dhcpv6
...
group <group-name1> {
   overrides {
      ...
      dual-stack <dual-stack-group-name> ;
   }
   ...
   interface pp0.0; <<<<< delete and add to new group
   ...
   }
group <group-name2> { <<<<< new group for PP0 interfaces to be handled separately.
   ...
   interface pp0.0; <<<<<
   ...
}