CVE-2024-39536

/// Technical description

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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References