CVE-2024-39531: Juniper Junos OS Evolved

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

An Improper Handling of Values vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX 7000 Series allows a network-based, unauthenticated attacker to cause a Denial-of-Service (DoS). If a value is configured for DDoS bandwidth or burst parameters for any protocol in a queue, all protocols which share the same queue will have their bandwidth or burst value changed to the new value. If, for example, OSPF was configured with a certain bandwidth value, ISIS would also be limited to this value. So inadvertently either the control plane is open for a high level of specific traffic which was supposed to be limited to a lower value, or the limit for a certain protocol is so low that chances to succeed with a volumetric DoS attack are significantly increased.  This issue affects Junos OS Evolved on ACX 7000 Series: * All versions before 21.4R3-S7-EVO, * 22.1 versions before 22.1R3-S6-EVO,  * 22.2 versions before 22.2R3-S3-EVO, * 22.3 versions before 22.3R3-S3-EVO,  * 22.4 versions before 22.4R3-S2-EVO, * 23.2 versions before 23.2R2-EVO, * 23.4 versions before 23.4R1-S1-EVO, 23.4R2-EVO.

Affected products

• Juniper Junos OS Evolved: before 21.4 (fixed in 21.4); version 21.4 only; version 22.1 only; version 22.2 only; version 22.3 only; version 22.4 only; …

Published 2024-07-11. Last modified 2026-06-17.