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

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

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

https://supportportal.juniper.net/JSA96452