CVE-2024-39536

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

MEDIUM

5.3

CVSS Score

Published: July 11, 2024 at 04:13 PM UTC

Updated: June 17, 2026 at 07:42 AM UTC

3 products affected across 2 vendorsJunosJunos OS EvolvedJunos OS Evolved

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Severity

MEDIUM5.3

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos OS Evolved · Juniper

95%

v < 21.221.2-EVO ≤ v < 21.2R3-S8-EVO21.4-EVO ≤ v < 21.4R3-S7-EVO22.2-EVO ≤ v < 22.2R3-S4-EVO22.3-EVO ≤ v < 22.3R3-EVO22.4-EVO ≤ v < 22.4R3-EVO23.2-EVO ≤ v < 23.2R1-EVO21.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.2 r3-s3 21.2 r3-s4 21.2 r3-s5 21.2 r3-s6 21.2 r3-s7 21.2-EVO 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 21.4 r3-s5 21.4 r3-s6 21.4-EVO 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.2 r3-s1 22.2 r3-s2 22.2 r3-s3 22.2-EVO 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3 r2-s2 22.3-EVO 22.4 22.4 r1 22.4 r1-s1 22.4 r1-s2 22.4 r2 22.4 r2-s1 22.4 r2-s2 22.4-EVO 23.2-EVO

Affected range stops below 21.2R3-S8-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S7-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S4-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R3-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.2R1-EVO, so it looks safe — our inference, not a vendor statement

Junos · Juniper Networks

95%

v < 21.2v < 21.2R3-S821.4 ≤ v < 21.4R3-S722.1 ≤ v < 22.1R3-S422.2 ≤ v < 22.2R3-S422.3 ≤ v < 22.3R322.4 ≤ v < 22.4R2-S222.4 ≤ v < 22.4R2-S2, 22.4R322.4 ≤ v < 22.4R321.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 21.4 r3-s5 21.4 r3-s6 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.1 r3 22.1 r3-s1 22.1 r3-s2 22.1 r3-s3 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.2 r3-s1 22.2 r3-s2 22.2 r3-s3 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3 r2-s2 22.4 22.4 r1 22.4 r1-s1 22.4 r1-s2 22.4 r2 22.4 r2-s1 22.4 r3

Affected range stops below 21.2R3-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R2-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R2-S2, 22.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R3, so it looks safe — our inference, not a vendor statement

Junos OS Evolved · Juniper Networks

60%

21.2-EVO ≤ v < 21.2R3-S8-EVO21.4-EVO ≤ v < 21.4R3-S7-EVO22.2-EVO ≤ v < 22.2R3-S4-EVO22.3-EVO ≤ v < 22.3R3-EVO22.4-EVO ≤ v < 22.4R3-EVO23.2-EVO ≤ v < 23.2R1-EVO21.2-EVO 21.4-EVO 22.2-EVO 22.3-EVO 22.4-EVO 23.2-EVO

Affected range stops below 21.2R3-S8-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S7-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S4-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R3-EVO, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.2R1-EVO, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://supportportal.juniper.net/JSA82996

References (1)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA82996

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMjuniper

Attack Vector: ADJACENT_NETWORK
Complexity: HIGH
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-401

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