CVE-2025-21600

Junos OS and Junos OS Evolved: With certain BGP options enabled, receipt of specifically malformed BGP update causes RPD crash

Description

An Out-of-Bounds Read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects systems configured in either of two ways: * systems with BGP traceoptions enabled * systems with BGP family traffic-engineering (BGP-LS) configured and can be exploited from a directly connected and configured BGP peer.  This issue affects iBGP and eBGP with any address family configured, 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;  Junos OS Evolved:  * from 21.4-EVO before 21.4R3-S9-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-S5-EVO,  * from 23.2-EVO before 23.2R2-S3-EVO,  * from 23.4-EVO before 23.4R2-S2-EVO,  * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect versions of Junos OS prior to 21.3R1. This issue does not affect versions of Junos OS Evolved prior to 21.3R1-EVO. This is a similar, but different vulnerability than the issue reported as CVE-2024-39516.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS: 21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases. Junos OS Evolved: 21.4R3-S9-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S2-EVO, 24.2R1-S2-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.

Workaround:

  • If BGP traceoptions are enabled, and traffic engineering is not configured, disable BGP traceoptions if they are not being used for active troubleshooting.

Category

7.1
CVSS
Severity: High
CVSS 4.0 •
CVSS 3.1 •
EPSS 0.06%
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-2025-21600?
CVE-2025-21600 has been scored as a high severity vulnerability.
How to fix CVE-2025-21600?
To fix CVE-2025-21600: The following software releases have been updated to resolve this specific issue: Junos OS: 21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases. Junos OS Evolved: 21.4R3-S9-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S2-EVO, 24.2R1-S2-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.
Is CVE-2025-21600 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-21600 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-21600?
CVE-2025-21600 affects Juniper Networks Junos OS, Juniper Networks Junos OS Evolved.
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