Juniper Networks Junos OS/Junos OS Evolved Routing Protocol Daemon exceptional condition

Summaryinfo

A vulnerability identified as critical has been detected in Juniper Networks Junos OS and Junos OS Evolved. This affects an unknown part of the component Routing Protocol Daemon. Performing a manipulation results in exceptional condition. This vulnerability is known as CVE-2025-21602. Access to the local network is required for this attack. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Juniper Networks Junos OS and Junos OS Evolved (affected version not known). It has been classified as critical. This affects some unknown functionality of the component Routing Protocol Daemon. The manipulation with an unknown input leads to a exceptional condition vulnerability. CWE is classifying the issue as CWE-755. The product does not handle or incorrectly handles an exceptional condition. This is going to have an impact on availability. The summary by CVE is:

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 before 22.4R3-S5-EVO,  * from 23.2 before 23.2R2-S3-EVO,  * from 23.4 before 23.4R2-S3-EVO,  * from 24.2 before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect versions prior to 21.1R1-EVO

The weakness was published by Craig Dods as JSA92872. The advisory is shared at supportportal.juniper.net. This vulnerability is uniquely identified as CVE-2025-21602 since 12/26/2024. The exploitability is told to be easy. The attack can only be initiated within the local network. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/26/2026).

The vulnerability scanner Nessus provides a plugin with the ID 213556 (Juniper Junos OS Vulnerability (JSA92872)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (213556). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Juniper Networks

Name

• Junos OS
• Junos OS Evolved

License

• commercial

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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