An Unchecked Return Value vulnerability in the authd (authentication daemon) of Juniper Networks Junos OS on MX Series configured for subscriber management / BBE allows an adjacent attacker to cause a crash by sending a specific username. This impacts authentication, authorization, and accounting (AAA) services on the MX devices and leads to a Denial of Service (DoS) condition. Continued receipted of these PPP login request will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS 15.1 versions prior to 15.1R7-S9.

17.3 versions prior to 17.3R3-S12.

17.4 versions prior to 17.4R3-S5.

18.1 versions prior to 18.1R3-S13.

18.2 versions prior to 18.2R3-S8.

18.3 versions prior to 18.3R3-S5.

18.4 versions prior to 18.4R3-S9.

19.1 versions prior to 19.1R3-S6.

19.2 versions prior to 19.2R1-S7, 19.2R3-S3.

19.3 versions prior to 19.3R2-S6, 19.3R3-S3.

19.4 versions prior to 19.4R3-S3.

20.1 versions prior to 20.1R3.

20.2 versions prior to 20.2R3-S1.

20.3 versions prior to 20.3R3.

20.4 versions prior to 20.4R3.

21.1 versions prior to 21.1R2.