CVE-2024-21606: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

A Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). In a remote access VPN scenario, if a "tcp-encap-profile" is configured and a sequence of specific packets is received, a flowd crash and restart will be observed. This issue affects Juniper Networks Junos OS on SRX Series: * All versions earlier than 20.4R3-S8; * 21.2 versions earlier than 21.2R3-S6; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3-S3; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S1; * 22.4 versions earlier than 22.4R2-S2, 22.4R3.

Affected products

• Juniper Junos: before 20.4 (fixed in 20.4); version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; …

Published 2024-01-12. Last modified 2026-06-17.