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JunosOperating system · Juniper

CVE-2024-39518

HIGH · 7.5 CVSS v3.1 Published 2024-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Heap-based Buffer Overflow vulnerability in the telemetry sensor process (sensord) of Juniper Networks Junos OS on MX240, MX480, MX960 platforms using MPC10E causes a steady increase in memory utilization, ultimately leading to a Denial of Service (DoS). When the device is subscribed to a specific subscription on Junos Telemetry Interface, a slow memory leak occurs and eventually all resources are consumed and the device becomes unresponsive. A manual reboot of the Line Card will be required to restore the device to its normal functioning.  This issue is only seen when telemetry subscription is active. The Heap memory utilization can be monitored using the following command:   > show system processes extensive The following command can be used to monitor the memory utilization of the specific sensor   > show system info | match sensord PID NAME MEMORY PEAK MEMORY %CPU THREAD-COUNT CORE-AFFINITY UPTIME 1986 sensord 877.57MB 877.57MB 2 4 0,2-15 7-21:41:32 This issue affects Junos OS:  * from 21.2R3-S5 before 21.2R3-S7,  * from 21.4R3-S4 before 21.4R3-S6,  * from 22.2R3 before 22.2R3-S4,  * from 22.3R2 before 22.3R3-S2,  * from 22.4R1 before 22.4R3,  * from 23.2R1 before 23.2R2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Heap-based buffer overflow in Junos OS sensord (telemetry sensor process) on MX240/MX480/MX960 platforms with MPC10E causes a slow memory leak when a specific telemetry subscription is active, eventually consuming all resources and requiring manual line card reboot for recovery.

MitigationUpgrade Junos OS to the fixed versions (21.2R3-S7, 21.4R3-S6, 22.2R3-S4, 22.3R3-S2, 22.4R3, 23.2R2 or later). Monitor sensord memory usage with 'show system processes extensive' and 'show system info | match sensord' as a detection method until patching is possible.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JunosOperating system
Affected:= 21.2= 21.4= 22.2= 22.3= 22.4= 23.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify platform is MX240, MX480, or MX960
    Run 'show chassis hardware' or 'show system hardware' to confirm the router model
    Affected if The platform is not one of these three models - the vulnerability does not apply
  2. Confirm MPC10E line cards are present
    Run 'show chassis hardware' and look for MPC10E line cards in the inventory
    Affected if No MPC10E line cards are installed - the vulnerability cannot be triggered
  3. Check Junos OS version against affected releases
    Run 'show version' and compare the installed version to 21.2, 21.4, 22.2, 22.3, 22.4, or 23.2
    Affected if The version does not match one of the listed affected versions - the system is not vulnerable to this CVE
  4. Monitor sensord process memory usage
    Run 'show system processes extensive | match sensord' repeatedly over time to observe memory consumption growth
    Affected if The sensord process shows continuous memory growth that does not stabilize, indicating the heap-based buffer overflow leak is occurring
  5. Review active telemetry subscriptions
    Run 'show system subscriber-management telemetry' or 'show services analytics management' to list active telemetry subscriptions
    Affected if A specific telemetry subscription is active that triggers the flaw - the vulnerability requires this subscription to be present to manifest the memory leak

You are affected if your MX240/MX480/MX960 has MPC10E line cards, runs one of the affected Junos versions (21.2, 21.4, 22.2, 22.3, 22.4, or 23.2), and has a telemetry subscription that triggers the sensord memory leak observable via increasing memory usage.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Junos OS to the fixed versions (21.2R3-S7, 21.4R3-S6, 22.2R3-S4, 22.3R3-S2, 22.4R3, 23.2R2 or later). Monitor sensord memory usage with 'show system processes extensive' and 'show system info | match sensord' as a detection method until patching is possible.

Recommended fix High confidence

Upgrade to one of: 21.2R3-S7, 21.4R3-S6, 22.2R3-S4, 22.3R3-S2, 22.4R3, or 23.2R2 (whichever matches your release train)

  1. 1. Identify the current Junos OS version using 'show version' command
  2. 2. Verify the device is an MX240, MX480, or MX960 with MPC10E line cards using 'show chassis hardware'
  3. 3. Confirm the telemetry subscription is active that triggers the issue using 'show services analytics interface'
  4. 4. Schedule a maintenance window for the upgrade
  5. 5. Back up the current configuration using 'request system configuration backup'
  6. 6. Download the appropriate fixed Junos OS version for your platform: 21.2R3-S7, 21.4R3-S6, 22.2R3-S4, 22.3R3-S2, 22.4R3, or 23.2R2
  7. 7. Upload the Junos software image to the device using 'request system software add'
  8. 8. Reboot the device using 'request system reboot'
Caveat Standard Junos OS upgrade considerations apply - review release notes for any configuration changes or known issues before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-39518 in production — separate from our analysis above.

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