Vulnerability 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
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Juniper | Junos | <= 21.4 |
Related Weaknesses (CWE)
References
- https://supportportal.juniper.net/JSA96452Vendor Advisory
FAQ
What is CVE-2025-21601?
CVE-2025-21601 is a vulnerability with a CVSS score of 7.5 (HIGH). 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, MX2...
How severe is CVE-2025-21601?
CVE-2025-21601 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-21601?
Check the references section above for vendor advisories and patch information. Affected products include: Juniper Junos.