CVE-2025-21598

CVE-2025-21598 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 7.5. 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 Juniper Networks Junos OS and Junos OS Evolved's routing protocol daemon (rpd) allows an unauthenticated, network-based attacker to send malformed BGP packets to a device configured with packet receive trace options enabled to crash rpd. This issue affects: Junos OS:  * from 21.2R3-S8 before 21.2R3-S9,  * from 21.4R3-S7 before 21.4R3-S9,  * from 22.2R3-S4 before 22.2R3-S5,  * from 22.3R3-S2 before 22.3R3-S4,  * from 22.4R3 before 22.4R3-S5,  * from 23.2R2 before 23.2R2-S2,  * from 23.4R1 before 23.4R2-S1,  * from 24.2R1 before 24.2R1-S1, 24.2R2. Junos OS Evolved: * from 21.4R3-S7-EVO before 21.4R3-S9-EVO,  * from 22.2R3-S4-EVO before 22.2R3-S5-EVO,  * from 22.3R3-S2-EVO before 22.3R3-S4-EVO,  * from 22.4R3-EVO before 22.4R3-S5-EVO,  * from 23.2R2-EVO before 23.2R2-S2-EVO,  * from 23.4R1-EVO before 23.4R2-S1-EVO,  * from 24.2R1-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue requires a BGP session to be established. This issue can propagate and multiply through multiple ASes until reaching vulnerable devices. This issue affects iBGP and eBGP. This issue affects IPv4 and IPv6. An indicator of compromise may be the presence of malformed update messages in a neighboring AS which is unaffected by this issue: For example, by issuing the command on the neighboring device:  show log messages Reviewing for similar messages from devices within proximity to each other may indicate this malformed packet is propagating:   rpd[<pid>]: Received malformed update from <IP address> (External AS <AS#>) and   rpd[<pid>]: Malformed Attribute

Frequently asked questions

What is CVE-2025-21598?
An Out-of-bounds Read vulnerability in Juniper Networks Junos OS and Junos OS Evolved's routing protocol daemon (rpd) allows an unauthenticated, network-based attacker to send malformed BGP packets to a device configured with packet receive trace options enabled to crash rpd. This issue affects: Junos OS:  * from 21.2R3-S8 before 21.2R3-S9,  * from 21.4R3-S7 before 21.4R3-S9,  * from 22.2R3-S4 before 22.2R3-S5,  * from 22.3R3-S2 before 22.3R3-S4,  * from 22.4R3 before 22.4R3-S5,  * from 23.2R2 before 23.2R2-S2,  * from 23.4R1 before 23.4R2-S1,  * from 24.2R1 before 24.2R1-S1, 24.2R2. Junos OS Evolved: * from 21.4R3-S7-EVO before 21.4R3-S9-EVO,  * from 22.2R3-S4-EVO before 22.2R3-S5-EVO,  * from 22.3R3-S2-EVO before 22.3R3-S4-EVO,  * from 22.4R3-EVO before 22.4R3-S5-EVO,  * from 23.2R2-EVO before 23.2R2-S2-EVO,  * from 23.4R1-EVO before 23.4R2-S1-EVO,  * from 24.2R1-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue requires a BGP session to be established. This issue can propagate and multiply through multiple ASes until reaching vulnerable devices. This issue affects iBGP and eBGP. This issue affects IPv4 and IPv6. An indicator of compromise may be the presence of malformed update messages in a neighboring AS which is unaffected by this issue: For example, by issuing the command on the neighboring device:  show log messages Reviewing for similar messages from devices within proximity to each other may indicate this malformed packet is propagating:   rpd[<pid>]: Received malformed update from <IP address> (External AS <AS#>) and   rpd[<pid>]: Malformed Attribute
How severe is CVE-2025-21598?
CVE-2025-21598 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-21598 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21598?
CVE-2025-21598 primarily affects Juniper Junos. In total, 37 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21598?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-21598 have an EU (EUVD) identifier?
Yes. CVE-2025-21598 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2564.
When was CVE-2025-21598 published?
CVE-2025-21598 was published on 2025-01-09 and last updated on 2026-06-17.

References

Affected products (37)

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