A Stack-based Buffer Overflow vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).

On all Junos OS MX Series platforms with SPC3 and MS-MPC/-MIC, when URL filtering is enabled and a specific URL request is received and processed, flowd will crash and restart. Continuous reception of the specific URL request will lead to a sustained Denial of Service (DoS) condition.

This issue affects Junos OS:

• All versions before 21.2R3-S6;
• from 21.3 before 21.3R3-S5;
• from 21.4 before 21.4R3-S5;
• from 22.1 before 22.1R3-S3;
• from 22.2 before 22.2R3-S1;
• from 22.3 before 22.3R2-S2, 22.3R3;
• from 22.4 before 22.4R2-S1, 22.4R3.

For the issue to occur, the following two conditions need to be met:
1. Enable URL filtering:
     [jservices-urlf enable]
2. Configure the following template
    [url-filter-template template {client-interfaces [] server-interfaces [] dns-server <IP_address> url-filter-database <db_name>}]
 

The following software releases have been updated to resolve this specific issue: 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2, 22.3R3, 22.4R2-S1, 22.4R3, 23.2R1, and all subsequent releases.

This issue is being tracked as 1731552 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).

2024-09-13: Minor formatting change to cvss field.
2024-04-10: 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
• https://www.cve.org/CVERecord?id=CVE-2024-30392