Juniper Networks Junos OS/Junos OS Evolved BGP UPDATE Packet resource control

Summaryinfo

A vulnerability was found in Juniper Networks Junos OS and Junos OS Evolved. It has been rated as critical. Affected by this vulnerability is an unknown functionality of the component BGP UPDATE Packet Handler. This manipulation causes resource control. This vulnerability appears as CVE-2025-21593. The attacker needs to be present on the local network. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Juniper Networks Junos OS and Junos OS Evolved (version unknown) and classified as critical. Affected by this vulnerability is an unknown function of the component BGP UPDATE Packet Handler. The manipulation with an unknown input leads to a resource control vulnerability. The CWE definition for the vulnerability is CWE-664. The product does not maintain or incorrectly maintains control over a resource throughout its lifetime of creation, use, and release. As an impact it is known to affect availability. The summary by CVE is:

An Improper Control of a Resource Through its Lifetime vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker to cause a Denial-of-Service (DoS). On devices with SRv6 (Segment Routing over IPv6) enabled, an attacker can send a malformed BGP UPDATE packet which will cause the rpd to crash and restart. Continued receipt of these UPDATE packets will cause a sustained DoS condition.  This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.This issue affects Junos OS:  * All versions before 21.2R3-S9,  * from 21.4 before 21.4R3-S10,  * from 22.2 before 22.2R3-S5,  * from 22.3 before 22.3R3-S4,  * from 22.4 before 22.4R3-S3,  * from 23.2 before 23.2R2-S2,  * from 23.4 before 23.4R2; and Junos OS Evolved:  * All versions before 21.2R3-S9-EVO,  * from 21.4-EVO before 21.4R3-S10-EVO,  * from 22.2-EVO before 22.2R3-S5-EVO,  * from 22.3-EVO before 22.3R3-S4-EVO,  * from 22.4-EVO before 22.4R3-S3-EVO, * from 23.2-EVO before 23.2R2-S2-EVO,  * from 23.4-EVO before 23.4R2-EVO.

It is possible to read the advisory at supportportal.juniper.net. This vulnerability is known as CVE-2025-21593 since 12/26/2024. The exploitation appears to be easy. The attack needs to approached within the local network. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 264549 (Juniper Junos OS Vulnerability (JSA92861)), 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 (264549). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Juniper Networks

Name

• Junos OS
• Junos OS Evolved

License

• commercial

CPE 2.3info

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CPE 2.2info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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