CVE-2025-21601

published 2025-04-09

CVE-2025-21601: An Improper Following of Specification by Caller vulnerability in web management (J-Web, Captive Portal, 802.1X, Juniper Secure Connect (JSC) of Juniper…

Priority P3 46 high 7.5 CVSS 3.1

AV N AC L PR N UI N S U C N I N A H

An Improper Following of Specification by Caller vulnerability in web management (J-Web, Captive Portal, 802.1X, Juniper Secure Connect (JSC) of Juniper Networks Junos OS on SRX Series, EX Series, MX240, MX480, MX960, QFX5120 Series, allows an unauthenticated, network-based attacker, sending genuine traffic targeted to the device to cause the CPU to climb until the device becomes unresponsive.

Continuous receipt of these packets will create a sustained Denial of Service (DoS) condition.

This issue affects Junos OS:

* All versions before 21.4R3-S9,
* from 22.2 before 22.2R3-S5,
* from 22.4 before 22.4R3-S4,
* from 23.2 before 23.2R2-S3,
* from 23.4 before 23.4R2-S3,
* from 24.2 before 24.2R1-S1, 24.2R2.

An indicator of compromise is to review the CPU % of the httpd process in the CLI:
e.g.
show system processes extensive | match httpd PID nobody 52 0 20M 191M select 2 0:01 80.00% httpd{httpd} <<<<< the percentage of httpd usage if high may be an indicator

Affected

18 ranges

Vendor	Product	Version range	Fixed in
juniper	ex_series	—	—
juniper	j-web	—	—
juniper	junos	<= 21.4	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos_os	—	—
juniper	qfx_series	—	—
juniper	srx_series	—	—
juniper_networks	junos_os	< 21.4R3-S9	21.4R3-S9
juniper_networks	junos_os	>= 22.2 < 22.2R3-S5	22.2R3-S5
juniper_networks	junos_os	>= 22.4 < 22.4R3-S4	22.4R3-S4
juniper_networks	junos_os	>= 23.2 < 23.2R2-S3	23.2R2-S3
juniper_networks	junos_os	>= 23.4 < 23.4R2-S3	23.4R2-S3
juniper_networks	junos_os	>= 24.2 < 24.2R1-S1, 24.2R2	24.2R1-S1, 24.2R2

CVSS provenance

nvd v3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd v4.0 8.7 HIGH CVSS:4.0/AV:N/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:Y/R:A/V:C/RE:M/U:Amber

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CWE-573