CVE-2025-21600: Junos OS and Junos OS Evolved: With certain BGP options enabled, receipt of specifically malformed BGP update causes RPD crash

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-01-09 · updated 2026-06-17
Weakness: CWE-125

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.

Affected products

Juniper Junos OS: 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+63)
Juniper Networks Junos OS Evolved: 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+61)

References

https://supportportal.juniper.net/JSA92870

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