CVE-2025-21596

Summary

An Improper Handling of Exceptional Conditions vulnerability in the command-line processing of Juniper Networks Junos OS on SRX1500, SRX4100, and SRX4200 devices allows a local, low-privileged authenticated attacker executing the 'show chassis environment pem' command to cause the chassis daemon (chassisd) to crash and restart, resulting in a temporary Denial of Service (DoS). However, repeated execution of this command will eventually cause the chassisd process to fail to restart, impacting packet processing on the system.

This issue affects Junos OS on SRX1500, SRX4100, SRX4200: 

  • All versions before 21.4R3-S9, 
  • from 22.2 before 22.2R3-S5, 
  • from 22.3 before 22.3R3-S4, 
  • from 22.4 before 22.4R3-S4, 
  • from 23.2 before 23.2R2-S3, 
  • from 23.4 before 23.4R2-S1.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OS0 < 21.4R3-S9affected
Juniper NetworksJunos OS22.2 < 22.2R3-S5affected
Juniper NetworksJunos OS22.3 < 22.3R3-S4affected
Juniper NetworksJunos OS22.4 < 22.4R3-S4affected
Juniper NetworksJunos OS23.2 < 23.2R2-S3affected
Juniper NetworksJunos OS23.4 < 23.4R2-S1affected

Weaknesses

  • CWE-755: CWE-755 Improper Handling of Exceptional Conditions

Workarounds

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 'show chassis environment pem' command.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References