Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2025-21601

Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
09/04/2025
Last modified:
11/08/2025

Description

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. <br /> <br /> Continuous receipt of these packets will create a sustained Denial of Service (DoS) condition.<br /> <br /> <br /> <br /> <br /> This issue affects Junos OS: <br /> <br /> <br /> <br /> * All versions before 21.4R3-S9,<br /> * from 22.2 before 22.2R3-S5,<br /> * from 22.4 before 22.4R3-S4,<br /> * from 23.2 before 23.2R2-S3,<br /> * from 23.4 before 23.4R2-S3,<br /> * from 24.2 before 24.2R1-S1, 24.2R2.<br /> <br /> <br /> An indicator of compromise is to review the CPU % of the httpd process in the CLI:<br /> e.g.<br />   show system processes extensive | match httpd  PID nobody       52   0   20M    191M select   2   0:01   80.00% httpd{httpd}

Impact

Vector 4.0
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/AU:Y/R:A/V:C/RE:M/U:Amber CVSS v4.0 Severity and Metrics:

Base Score: 8.70 HIGH
Vector: 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/AU:Y/R:A/V:C/RE:M/U:Amber

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): Low
Automatable (AU): Yes
Recovery (R): Automatic
Value Density (V): Concentrated
Vulnerability Response Effort (RE): Moderate
Provider Urgency (U): Amber

Base Score 4.0
8.70
Severity 4.0
HIGH
Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
7.50
Severity 3.x
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* 21.4 (including)
cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3-s7:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools