Juniper Junos OS 12.1X44 before 12.1X44-D50 12.1X46 before 12.1X46-D35 12.1X47 before 12.1X47-D25 12.3 before 12.3R9 12.3X48 before 12.3X48-D15 13.2 before 13.2R7 13.2X51 before 13.2X51-D35 13.2X52 before 13.2X52-D25 13.3 before 13.3R6 14.1R3 before 14.1R3-S2 14.1 before 14.1R4 14.1X53 before 14.1X53-D12 14.1X53 before 14.1X53-D16 14.1X55 before 14.1X55-D25 14.2 before 14.2R2 and 15.1 before 15.1R1 allows remote attackers to cause a denial of service (mbuf and connection consumption and restart) via a large number of requests that trigger a TCP connection to move to the LAST_ACK state when there is more data to send.