A Missing Release of Memory after Effective Lifetime vulnerability in the Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). In an IPsec VPN environment, a memory leak will be seen if a DH or ECDH group is configured. Eventually the flowd process will crash and restart. This issue affects Juniper Networks Junos OS on SRX Series: All versions prior to 19.3R3-S7; 19.4 versions prior to 19.4R2-S8, 19.4R3-S10; 20.2 versions prior to 20.2R3-S6; 20.3 versions prior to 20.3R3-S5; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3; 21.3 versions prior to 21.3R3; 21.4 versions prior to 21.4R2.