CVE-2025-52946

Junos OS and Junos OS Evolved: With traceoptions enabled, receipt of malformed AS PATH causes RPD crash

Description

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).

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS 21.2R3-S9, 22.2R3-S6, 22.4R3-S5, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases. Junos OS Evolved: 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.

Workaround:

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

Category

8.7
CVSS
Severity: High
CVSS 4.0 •
CVSS 3.1 •
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Affected: Juniper Networks Junos OS Evolved
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2025-52946?
CVE-2025-52946 has been scored as a high severity vulnerability.
How to fix CVE-2025-52946?
To fix CVE-2025-52946: The following software releases have been updated to resolve this specific issue: Junos OS 21.2R3-S9, 22.2R3-S6, 22.4R3-S5, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases. Junos OS Evolved: 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.
Is CVE-2025-52946 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-52946 is being actively exploited.
What software or system is affected by CVE-2025-52946?
CVE-2025-52946 affects Juniper Networks Junos OS, Juniper Networks Junos OS Evolved.
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