Skip to content
Fencer Vulns
medium 5.3

CVE-2024-39536 json

Junos OS and Junos OS Evolved: Flaps of BFD sessions with authentication cause a ppmd memory leak

published 2024-07-11 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-38062

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

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.

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S8, 21.4R3-S7, 22.1R3-S4, 22.2R3-S4, 22.3R3, 22.4R2-S2, 22.4R3
  • Juniper Networks Junos OS Evolved 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-EVO, 22.4R3-EVO, 23.2R1-EVO
  • juniper junos_os 21.2R3-S8, 21.4R3-S7, 22.1R3-S4, 22.2R3-S4, 22.3R3, 22.4R2-S2, 22.4R3
  • juniper junos_os_evolved 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-EVO, 22.4R3-EVO, 23.2R1-EVO

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 6.0 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
CNA 4.0 6.0 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

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved
  • juniper junos_os
  • juniper junos_os_evolved

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.