6.7

CVE-2026-21901

Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash

A NULL Pointer Dereference vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker setting or deactivating a specific SSH configuration parameter to create a Denial of Service (DoS).

A local high-privileged user configuring or deactivating a specific 'system services ssh' configuration parameter can exploit a null pointer dereference in one of the functions used by SSH. The function attempts to dereference a null pointer when accessing certain configuration data, resulting in an mgd process crash and restart. Continued execution of these configuration commands will create a sustained Denial of Service (DoS) condition.

This issue affects:
Junos OS:


  *  from 22.3 before 22.3R3-S5;
  *  from 22.4 before 22.4R3-S10;
  *  from 23.2 before 23.2R2-S7;
  *  from 23.4 before 23.4R2-S8.




This issue does not affect Junos OS before 22.3R1.



Junos OS Evolved:
  *  from 22.3R1-EVO before 23.2R2-S7-EVO;
  *  from 23.4 before 23.4R2-S8-EVO.


This issue does not affect Junos OS Evolved before 22.3R1-EVO.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerJuniper Networks
≫
Produkt Junos OS
Default Statusunaffected
Version 22.3
Version < 22.3R3-S5
Status affected
Version 22.4
Version < 22.4R3-S10
Status affected
Version 23.2
Version < 23.2R2-S7
Status affected
Version 23.4
Version < 23.4R2-S8
Status affected
Version 0
Version < 22.3R1
Status unaffected
HerstellerJuniper Networks
≫
Produkt Junos OS Evolved
Default Statusunaffected
Version 23.2
Version < 23.2R2-S7-EVO
Status affected
Version 23.4
Version < 23.4R2-S8-EVO
Status affected
Version 0
Version < 22.3R1-EVO
Status unaffected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
sirt@juniper.net 4.4 0.8 3.6
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
sirt@juniper.net 6.7 0 0
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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:D/RE:M/U:Green
CWE-476 NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

https://github.com/orangecertcc/security-research/security/advisories/GHSA-g4f7-w2rc-hpj6
https://supportportal.juniper.net/JSA110072