CVE-2024-39536: Juniper Junos

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

A Missing Release of Memory after Effective Lifetime vulnerability in the Periodic Packet Management Daemon (ppmd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS). When a BFD session configured with authentication flaps, ppmd memory can leak. Whether the leak happens depends on a race condition which is outside the attackers control. This issue only affects BFD operating in distributed aka delegated (which is the default behavior) or inline mode. Whether the leak occurs can be monitored with the following CLI command: > show ppm request-queue FPC     Pending-request fpc0                   2 request-total-pending: 2 where a continuously increasing number of pending requests is indicative of the leak.  This issue affects: Junos OS: * All versions before 21.2R3-S8, * 21.4 versions before 21.4R3-S7, * 22.1 versions before 22.1R3-S4, * 22.2 versions before 22.2R3-S4, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R2-S2, 22.4R3. Junos OS Evolved: * All versions before 21.2R3-S8-EVO, * 21.4-EVO versions before 21.4R3-S7-EVO, * 22.2-EVO versions before 22.2R3-S4-EVO, * 22.3-EVO versions before 22.3R3-EVO, * 22.4-EVO versions before 22.4R3-EVO.

Affected products

• Juniper Junos: before 21.2 (fixed in 21.2); version 21.4 only; version 22.1 only; version 22.2 only; version 22.3 only; version 22.4 only
• Juniper Junos OS Evolved: before 21.2 (fixed in 21.2); version 21.2 only; version 21.4 only; version 22.2 only; version 22.3 only; version 22.4 only

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