CVE-2024-39529: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

A Use of Externally-Controlled Format String vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If DNS Domain Generation Algorithm (DGA) detection or tunnel detection, and DNS-filtering traceoptions are configured, and specific valid transit DNS traffic is received this causes a PFE crash and restart, leading to a Denial of Service. This issue affects Junos OS: * All versions before 21.4R3-S6, * 22.2 versions before 22.2R3-S3, * 22.3 versions before 22.3R3-S3, * 22.4 versions before 22.4R3, * 23.2 versions before 23.2R2.

Affected products

• Juniper Junos: before 21.4 (fixed in 21.4); version 21.4 only; version 22.2 only; version 22.3 only; version 22.4 only; version 23.2 only

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