CVE-2025-21600

CVE-2025-21600 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

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.

Frequently asked questions

What is CVE-2025-21600?
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.
How severe is CVE-2025-21600?
CVE-2025-21600 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-21600 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21600?
CVE-2025-21600 primarily affects Juniper Junos. In total, 136 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21600?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21600 have an EU (EUVD) identifier?
Yes. CVE-2025-21600 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2566.
When was CVE-2025-21600 published?
CVE-2025-21600 was published on 2025-01-09 and last updated on 2026-06-17.

References

Affected products (136)

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