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Fencer Intel
medium 6.5

CVE-2025-21602 json

Junos OS and Junos OS Evolved: Receipt of specially crafted BGP update packet causes RPD crash

published last yr. modified 4mo ago also EUVD-2025-2567

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker sending a specific BGP update packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS).

Continuous receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

This issue affects iBGP and eBGP, 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;

This issue does not affect versions prior to 21.1R1.

Junos OS Evolved:

* from 21.4 before 21.4R3-S9-EVO,  * from 22.2 before 22.2R3-S5-EVO,  * from 22.3 before 22.3R3-S4-EVO, * from 22.4 before 22.4R3-S5-EVO,  * from 23.2 before 23.2R2-S3-EVO,  * from 23.4 before 23.4R2-S3-EVO,  * from 24.2 before 24.2R1-S2-EVO, 24.2R2-EVO.

This issue does not affect versions prior to 21.1R1-EVO

Patch / fix

  • Juniper Networks 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
  • Juniper Networks 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-S3-EVO, 24.2R1-S2-EVO, 24.2R2-EVO

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 7.1 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:N/R:A/V:C/RE:M/U:Green
CNA 4.0 7.1 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:A/V:C/RE:M/U:Green

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.