CVE-2025-52946

Summary

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).

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OS0 < 21.2R3-S9affected
Juniper NetworksJunos OS21.4 < *affected
Juniper NetworksJunos OS22.2 < 22.2R3-S6affected
Juniper NetworksJunos OS22.4 < 22.4R3-S5affected
Juniper NetworksJunos OS23.2 < 23.2R2-S3affected
Juniper NetworksJunos OS23.4 < 23.4R2-S4affected
Juniper NetworksJunos OS24.2 < 24.2R2affected
Juniper NetworksJunos OS Evolved0 < 22.4R3-S5-EVOaffected
Juniper NetworksJunos OS Evolved23.2-EVO < 23.2R2-S3-EVOaffected
Juniper NetworksJunos OS Evolved23.4-EVO < 23.4R2-S4-EVOaffected
Juniper NetworksJunos OS Evolved24.2-EVO < 24.2R2-EVOaffected

Weaknesses

  • CWE-416: CWE-416 Use After Free

Workarounds

Disable BGP traceoptions if they are not being used for active troubleshooting.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References