Product Affected

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

CVSS: v3.1: 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVSS: v4.0: 6.8 (CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:A)

Problem

An Improper Handling of Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged attacker executing a CLI command to cause a Denial of Service (DoS).

When 'asregex-optimize' is configured and a specific "show route as-path" CLI command is executed, the rpd crashes and restarts. Repeated execution of this command will cause a sustained DoS condition.

 

This issue affects Junos OS:

  • All versions before 21.2R3-S9,
  • from 21.4 before 21.4R3-S10,
  • from 22.2 before 22.2R3-S6,
  • from 22.4 before 22.4R3-S6,
  • from 23.2 before 23.2R2-S3,
  • from 23.4 before 23.4R2-S4,
  • from 24.2 before 24.2R2.

and Junos OS Evolved:
  • All versions before 21.2R3-S9-EVO,
  • from 21.4-EVO before 21.4R3-S10-EVO,
  • from 22.2-EVO before 22.2R3-S6-EVO,
  • from 22.4-EVO before 22.4R3-S6-EVO,
  • from 23.2-EVO before 23.2R2-S3-EVO,
  • from 23.4-EVO before 23.4R2-S4-EVO,
  • from 24.2-EVO before 24.2R2-EVO.

 

Required configuration for exposure:

[ edit policy-options defaults ]
[ asregex-optimize optimize ]

Solution

The following software releases have been updated to resolve this specific issue:
Junos OS: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases.
Junos OS Evolved: 21.2R3-S9-EVO, 21.4R3-S10-EVO, 22.2R3-S6-EVO, 22.4R3-S6-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1848929 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 'show route as-path' 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

2025-04-09: Initial Publication
2025-04-15: Corrected typo in Description (as-regex-optimized)

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