CVE-2025-21601 Details
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
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2025-21601
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.13 Probability of exploitation activity being observed over the next 30 days (33nd percentile)
CVSS score for CVE-2025-21601
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
7.5 High
Products affected by CVE-2025-21601
Junos 12.1x44
Junos 12.1x45
Junos 12.1x46
Junos 12.1x47
Junos 12.3x48
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Not available
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CVE-2025-21601 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
NA 26 26.53%
PK 8 8.16%
CA 6 6.12%
TW 6 6.12%
BD 5 5.10%
CN 4 4.08%
VN 4 4.08%
VE 4 4.08%
KR 4 4.08%
ZM 3 3.06%

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CVE-2025-21601 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Telecommunications 60 90.91%
Technology 3 4.55%
Business Services 1 1.52%
Consumer Goods 1 1.52%
Manufacturing 1 1.52%

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