SB2025050114 - Improper check for unusual or exceptional conditions in Junos OS Evolved and Juniper Junos OS

Security Bulletin ID SB2025050114

CSH Severity

Medium

Patch available

YES

Number of vulnerabilities 1

Exploitation vector Adjecent network

Highest impact Denial of service

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 1 vulnerability.

1) Improper check for unusual or exceptional conditions (CVE-ID: CVE-2025-21597)

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper check for unusual or exceptional conditions error in routing protocol daemon (rpd). A remote non-authenticated attacker can cause Denial of Service (DoS).

On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts.

Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.

Remediation

Install update from vendor's website.

References

https://supportportal.juniper.net/s/article/2025-04-Security-Bulletin-Junos-OS-and-Junos-OS-Evolved-When-BGP-rib-sharding-and-update-threading-are-configured-and-a-peer-flaps-an-rpd-core-is-observed