An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX4600 and SRX5000 Series allows an unauthenticated and logically adjacent attacker to cause a Denial-of-Service (DoS). If in a multicast scenario a sequence of specific PIM packets is received, this will cause a flowd crash and restart, which leads to momentary service interruption. This issue affects Junos OS on SRX 4600 and SRX 5000 Series: * All versions before 21.4R3-S9, * 22.2 versions before 22.2R3-S5, * 22.3 versions before 22.3R3-S4, * 22.4 versions before 22.4R3-S4, * 23.2 versions before 23.2R2-S2, * 23.4 versions before 23.4R2,  * 24.2 versions before 24.2R1-S1, 24.2R2.