CVE-2024-39550

Junos OS: MX Series with SPC3 line card: Port flaps causes rtlogd memory leak leading to Denial of Service

MEDIUM
6.5
CVSS Score
Published: July 11, 2024 at 04:29 PM UTC
Updated: June 17, 2026 at 07:42 AM UTC
4 products affected across 2 vendorsJunosMx960Mx480

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the rtlogd process of Juniper Networks Junos OS on MX Series with SPC3 allows an unauthenticated, adjacent attacker to trigger internal events cause ( which can be done by repeated port flaps) to cause a slow memory leak, ultimately leading to a Denial of Service (DoS). Memory can only be recovered by manually restarting rtlogd process.  The memory usage can be monitored using the below command. user@host> show system processes extensive | match rtlog This issue affects Junos OS on MX Series with SPC3 line card: * from 21.2R3 before 21.2R3-S8,  * from 21.4R2 before 21.4R3-S6,  * from 22.1 before 22.1R3-S5,  * from 22.2 before 22.2R3-S3,  * from 22.3 before 22.3R3-S2,  * from 22.4 before 22.4R3-S1,  * from 23.2 before 23.2R2,  * from 23.4 before 23.4R2.

Affected

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

Affected range stops below 21.2R3-S8, so it looks safe — our inference, not a vendor statement
Affected range stops below 21.4R3-S6, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.1R3-S5, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.2R3-S3, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.3R3-S2, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.4R3-S1, so it looks safe — our inference, not a vendor statement
Affected range stops below 23.2R2, so it looks safe — our inference, not a vendor statement
Affected range stops below 23.4R2, so it looks safe — our inference, not a vendor statement
juniper-mx240 (environment) · juniper-mx480 (environment) · juniper-mx960 (environment)
All versions
All versions
All versions

Remediation

No guide yet

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

Patch and advisory references

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

6.5MEDIUMjuniper
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-401

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