An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS).

On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services.

Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability.

The memory usage can be monitored using the below commands.

This issue affects:

Junos OS

• 21.2 versions earlier than 21.2R3-S5;
• 21.3 versions earlier than 21.3R3-S4;
• 21.4 versions earlier than 21.4R3-S4;
• 22.1 versions earlier than 22.1R3-S2;
• 22.2 versions earlier than 22.2R3-S2;
• 22.3 versions earlier than 22.3R2-S1, 22.3R3;
• 22.4 versions earlier than 22.4R1-S2, 22.4R2.

To be exposed to this issue non-stop routing (NSR) needs to be configured:

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-2024-21617.

The following software releases have been updated to resolve this specific issue: 21.2R3-S5, 21.3R3-S4, 21.4R3-S4, 22.1R3-S2, 22.2R3-S2, 22.3R2-S1, 22.3R3, 22.4R1-S2, 22.4R2, 23.2R1, and all subsequent releases.

This issue is being tracked as PR 1711656 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).

2024-01-10: Initial Publication

2024-01-23: Clarified that the SRX Series does not support NSR, and is therefore not affected by this vulnerability

2024-02-01: Removed information related to 20.4 in the JSA as it was misleading.

• 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-2024-21617 at cve.mitre.org