An Improper Check for Unusual or Exceptional Conditions vulnerability in the processing of specific IPv6 packets on certain EX Series devices may lead to exhaustion of DMA memory causing a Denial of Service (DoS). Over time, exploitation of this vulnerability may cause traffic to stop being forwarded, or a crash of the fxpc process. An indication of the issue occurring may be observed through the following log messages: Sep 13 17:14:59 hostname : %PFE-3: fpc0 (buf alloc) failed allocating packet buffer Sep 13 17:14:59 hostname : %PFE-7: fpc0 brcm_pkt_buf_alloc:393 (buf alloc) failed allocating packet buffer When Packet DMA heap utilization reaches 99%, the system will become unstable. Packet DMA heap utilization can be monitored using the command: user@junos# request pfe execute target fpc0 timeout 30 command "show heap" ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 213301a8 536870488 387228840 149641648 27 Kernel 1 9180000…