{"cve":"CVE-2025-21601","nvd":{"published":"2025-04-09T20:15:26.350","modified":"2026-06-17T08:43:49.797","status":"Analyzed","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. \n\nContinuous receipt of these packets will create a sustained Denial of Service (DoS) condition.\n\n\n\n\nThis issue affects Junos OS: \n\n\n\n  *  All versions before 21.4R3-S9,\n  *  from 22.2 before 22.2R3-S5,\n  *  from 22.4 before 22.4R3-S4,\n  *  from 23.2 before 23.2R2-S3,\n  *  from 23.4 before 23.4R2-S3,\n  *  from 24.2 before 24.2R1-S1, 24.2R2.\n\n\nAn indicator of compromise is to review the CPU % of the httpd process in the CLI:\ne.g.\n  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_v4":{"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","score":8.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-573"],"references":["https://supportportal.juniper.net/JSA96452"],"products":["juniper:junos"],"source":"nvd","synced_at":"2026-10-19T22:00:57.946988208+00:00"},"epss":{"cve":"CVE-2025-21601","score":0.00424,"percentile":0.36736,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}