High severity · published Apr 9, 2025
CVE-2025-21601
Junos OS: SRX and EX Series, MX240, MX480, MX960, QFX5120 Series: When web management is enabled for specific services an attacker may cause a CPU spike by sending genuine packets to the device
7.5
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JO
Junos OS · Juniper
before 21.4R3-S9; 22.2 before 22.2R3-S5; 22.4 before 22.4R3-S4; 23.2 before 23.2R2-S3; 23.4 before 23.4R2-S3; 24.2 before 24.2R1-S1, 24.2R2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-21601
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-21601
Vendor Advisory
https://supportportal.juniper.net/JSA96452
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