In VxLAN scenarios on EX4300-MP, EX4600, QFX5000 Series devices an Uncontrolled Memory Allocation vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an unauthenticated adjacently located attacker sending specific packets to cause a Denial of Service (DoS) condition by crashing one or more PFE's when they are received and processed by the device. Upon automatic restart of the PFE, continued processing of these packets will cause the memory leak to reappear. Depending on the volume of packets received the attacker may be able to create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on EX4300-MP, EX4600, QFX5000 Series: 17.1 version 17.1R1 and later versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13, 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 18.4R1-S8, 18.4R2-S6, 18.4R3-S6; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R1-S7, 19.2R3-S1; 19.3 versions prior to 19.3R2-S6, 19.3R3-S1; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2. This issue does not affect Junos OS versions prior to 17.1R1.