CVE-2025-21601
Juniper Networks Junos OS SRX Series, EX Series, MX240, MX480, MX960, QFX5120 Series J-Web, Captive Portal, 802.1X, Juniper Secure Connect (JSC) Denial of Service (DoS)
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. 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
INFO
Published Date :
April 9, 2025, 8:15 p.m.
Last Modified :
Aug. 11, 2025, 3:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Junos OS to a fixed version.
- Monitor httpd process CPU usage for spikes.
- Review Juniper security advisories for patches.
- Implement network traffic filtering if possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-21601.
| URL | Resource |
|---|---|
| https://supportportal.juniper.net/JSA96452 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-21601 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-21601
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-21601 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-21601 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Aug. 11, 2025
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:* *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:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:* *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:22.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* *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:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.2:r3-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:21.4:r3-s8:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* versions up to (including) 21.4 Added Reference Type Juniper Networks, Inc.: https://supportportal.juniper.net/JSA96452 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 15, 2025
Action Type Old Value New Value Added CWE CWE-573 -
New CVE Received by [email protected]
Apr. 09, 2025
Action Type Old Value New Value Added 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. 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 Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added Reference https://supportportal.juniper.net/JSA96452