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).