Product Affected

This issue affects all versions of Junos OS and Junos OS Evolved.
Medium

Problem

An Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in the CLI of Juniper Networks Junos OS and Junos OS Evolved allows a high privileged, local attacker to escalated their privileges to root.

When a user provides specifically crafted arguments to the 'request system logout' command, these will be executed as root on the shell, which can completely compromise the device.

This issue affects:

Junos OS: 

  • all versions before 21.2R3-S9,
  • 21.4 versions before 21.4R3-S8,
  • 22.2 versions before 22.2R3-S6,
  • 22.3 versions before 22.3R3-S3,
  • 22.4 versions before 22.4R3-S6,
  • 23.2 versions before 23.2R2-S1,
  • 23.4 versions before 23.4R1-S2, 23.4R2;

 

Junos OS Evolved:

  • all versions before 22.4R3-S6-EVO,
  • 23.2-EVO versions before 23.2R2-S1-EVO,
  • 23.4-EVO versions before 23.4R1-S2-EVO, 23.4R2-EVO.

 

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

 

This issue was discovered during external security research.

Solution

The following software releases have been updated to resolve this specific issue:
Junos OS Evolved: 22.4R3-S6-EVO, 23.2R2-S1-EVO, 23.4R1-S2-EVO, 23.4R2-EVO, 24.2R1-EVO, and all subsequent releases;
Junos OS: 21.2R3-S9, 21.4R3-S8, 22.2R3-S6, 22.3R3-S3, 22.4R3-S6, 23.2R2-S1, 23.4R1-S2, 23.4R2, 24.2R1, and all subsequent releases.

 

This issue is being tracked as 1794613 which is visible on the Customer Support website.

 

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Workaround

Use access lists or firewall filters to limit access to the CLI only from trusted hosts and administrators.

Utilize CLI authorization to disallow execution of the 'request system logout' command.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History

2025-07-09: Initial Publication

2025-07-10: Add "to root" to the title to make it more obvious what the issue is

Related Information

Acknowledgements

Juniper SIRT would like to acknowledge and thank the National Security Agency for responsibly reporting this vulnerability.