An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX4600 and SRX5000 Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).

If a sequence of specific PIM packets is received, this will cause a flowd crash and restart, which leads to momentary service interruption.

This issue affects Junos OS on SRX 4600 and SRX 5000 Series:

• All versions before 21.4R3-S9,
• 22.2 versions before 22.2R3-S5,
• 22.3 versions before 22.3R3-S4,
• 22.4 versions before 22.4R3-S4,
• 23.2 versions before 23.2R2-S2,
• 23.4 versions before 23.4R2, 
• 24.2 versions before 24.2R1-S1, 24.2R2.

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

This issue was seen during production usage.

The following software releases have been updated to resolve this specific issue: 21.4R3-S9, 22.2R3-S5, 22.3R3-S4*, 22.4R3-S4, 23.2R2-S2, 23.4R2, 24.2R1-S1, 24.2R2*, 24.4R1*, and all subsequent releases.
(* future release)

This issue is being tracked as 1820291 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).

There are no known workarounds for this issue.

2024-10-09: Initial Publication
2024-11-08: Changed this from being an adjacent to a network vulnerability

• 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