CVE-2025-21602

/// Technical description

An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker sending a specific BGP update packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS).

Continuous receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.

This issue affects Junos OS: 

* from 21.4 before 21.4R3-S9, 

* from 22.2 before 22.2R3-S5, 

* from 22.3 before 22.3R3-S4,

* from 22.4 before 22.4R3-S5, 

* from 23.2 before 23.2R2-S3, 

* from 23.4 before 23.4R2-S3, 

* from 24.2 before 24.2R1-S2, 24.2R2; 

This issue does not affect versions prior to 21.1R1.

Junos OS Evolved: 

* from 21.4 before 21.4R3-S9-EVO, 

* from 22.2 before 22.2R3-S5-EVO, 

* from 22.3 before 22.3R3-S4-EVO,

* from 22.4 bef

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References