An Improper Validation of Syntactic Correctness of Input vulnerability in Routing Protocol Daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network based attacker to cause a Denial of Service (DoS). When a malformed BGP UPDATE packet is received over an established BGP session, the rpd crashes and restarts. This issue affects both eBGP and iBGP implementations. This issue affects: Juniper Networks Junos OS * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3; * 23.2 versions prior to 23.2R1, 23.2R2; Juniper Networks Junos OS Evolved * 21.4 versions prior to 21.4R3-S5-EVO; * 22.1 versions prior to 22.1R3-S3-EVO; * 22.2 versions prior to 22.2R3-S3-EVO; * 22.3 versions prior to 22.3R2-S2-EVO; * 22.4 versions prior to 22.4R3-EVO; * 23.2 versions prior to 23.2R2-EVO;