An Allocation of Resources Without Limits or Throttling vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS).

If a high rate of specific valid packets are processed by the routing engine (RE) this will lead to a loss of connectivity of the RE with other components of the chassis and thereby a complete and persistent system outage. Please note that a carefully designed lo0 firewall filter will block or limit these packets which should prevent this issue from occurring.

The following log messages can be seen when this issue occurs:

This issue affects Juniper Networks Junos OS Evolved:

• All versions earlier than 20.4R3-S7-EVO;
• 21.2R1-EVO and later versions;
• 21.4-EVO versions earlier than 21.4R3-S5-EVO;
• 22.1-EVO versions earlier than 22.1R3-S2-EVO;
• 22.2-EVO versions earlier than 22.2R3-EVO;
• 22.3-EVO versions earlier than 22.3R2-EVO;
• 22.4-EVO versions earlier than 22.4R2-EVO.

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

This issue was seen during production usage.

This issue has been assigned CVE-2024-21604.

The following software releases have been updated to resolve this specific issue: 20.4R3-S7-EVO, 21.4R3-S5-EVO, 22.1R3-S2-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.4R2-EVO, 23.2R1-EVO, and all subsequent releases.

This issue is being tracked as PR 1663122 and 1712937 which are 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).

2024-01-10: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2024-21604 at cve.mitre.org