An Improper Input Validation vulnerability in the VxLAN packet forwarding engine (PFE) of Juniper Networks Junos OS on QFX5000 Series, EX4600 Series devices allows an unauthenticated, adjacent attacker, sending two or more genuine packets in the same VxLAN topology to possibly cause a DMA memory leak to occur under various specific operational conditions. The scenario described here is the worst-case scenario. There are other scenarios that require operator action to occur. An indicator of compromise may be seen when multiple devices indicate that FPC0 has gone missing when issuing a show chassis fpc command for about 10 to 20 minutes, and a number of interfaces have also gone missing. Use the following command to determine if FPC0 has gone missing from the device. show chassis fpc detail This issue affects: Juniper Networks Junos OS on QFX5000 Series, EX4600 Series: * 18.4 version 18.4R2 and later versions prior to 20.4R3-S8; * 21.1 version 21.1R1 and later versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2.