An Improper Validation of Syntactic Correctness of Input vulnerability in the kernel of Juniper Networks Junos OS Evolved on PTX series allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). When an incoming TCP packet destined to the device is malformed there is a possibility of a kernel panic. Only TCP packets destined to the ports for BGP, LDP and MSDP can trigger this. This issue only affects PTX10004, PTX10008, PTX10016. No other PTX Series devices or other platforms are affected. This issue affects Juniper Networks Junos OS Evolved: 20.4-EVO versions prior to 20.4R3-S4-EVO; 21.3-EVO versions prior to 21.3R3-EVO; 21.4-EVO versions prior to 21.4R3-EVO; 22.1-EVO versions prior to 22.1R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 20.4R1-EVO.