CVE-2024-39536: A Missing Release of Memory after Effective Lifetime vulnerability in the Periodic Packet Management Daemon (ppmd) of Juniper Networks Junos OS and Ju...

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, * 22.3 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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

6/10

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.23%

13.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-401

Affected Software

Vendor	Product	Versions
Juniper	Junos	< 21.2
Juniper	Junos	21.4
Juniper	Junos	22.1
Juniper	Junos	22.2
Juniper	Junos	22.3
Juniper	Junos	22.4
Juniper	Junos Os Evolved	< 21.2
Juniper	Junos Os Evolved	21.2
Juniper	Junos Os Evolved	21.4
Juniper	Junos Os Evolved	22.2
Juniper	Junos Os Evolved	22.3
Juniper	Junos Os Evolved	22.4

References

https://supportportal.juniper.net/JSA82996Vendor Advisory
https://supportportal.juniper.net/JSA82996Vendor Advisory

Timeline

Published: Jul 11, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-39536?

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.

How severe is CVE-2024-39536?

CVE-2024-39536 has a CVSS score of 6/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2024-39536?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.