A Use After Free vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an attacker sending a BGP update with a specifically malformed AS PATH to cause rpd to crash, resulting in a Denial of Service (DoS). Continuous receipt of the malformed AS PATH attribute will cause a sustained DoS condition. On all Junos OS and Junos OS Evolved platforms, the rpd process will crash and restart when a specifically malformed AS PATH is received within a BGP update and traceoptions are enabled.

This issue only affects systems with BGP traceoptions enabled and requires a BGP session to be already established. Systems without BGP traceoptions enabled are not impacted by this issue. This issue affects: Junos OS: All versions before 21.2R3-S9, all versions of 21.4, from 22.2 before 22.2R3-S6, from 22.4 before 22.4R3-S5, from 23.2 before 23.2R2-S3, from 23.4 before 23.4R2-S4, from 24.2 before 24.2R2; Junos OS Evolved: All versions before 22.4R3-S5-EVO, from 23.2-EVO before 23.2R2-S3-EVO, from 23.4-EVO before 23.4R2-S4-EVO, * from 24.2-EVO before 24.2R2-EVO.

This is a more complete fix for previously published CVE-2024-39549 (JSA83011).