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JunosOperating system · Juniper

CVE-2024-30388

MEDIUM · 6.5 CVSS v3.1 Published 2024-04-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
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
An Improper Isolation or Compartmentalization vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on QFX5000 Series and EX Series allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS). If a specific malformed LACP packet is received by a QFX5000 Series, or an EX4400, EX4100 or EX4650 Series device, an LACP flap will occur resulting in traffic loss. This issue affects Junos OS on QFX5000 Series, and on EX4400, EX4100 or EX4650 Series: * 20.4 versions from 20.4R3-S4 before 20.4R3-S8, * 21.2 versions from 21.2R3-S2 before 21.2R3-S6, * 21.4 versions from 21.4R2 before 21.4R3-S4, * 22.1 versions from 22.1R2 before 22.1R3-S3, * 22.2 versions before 22.2R3-S1, * 22.3 versions before 22.3R2-S2, 22.3R3, * 22.4 versions before 22.4R2-S1, 22.4R3.

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

A vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on QFX5000 Series and EX Series (EX4400, EX4100, EX4650) allows an unauthenticated, adjacent attacker to send a malformed LACP (Link Aggregation Control Protocol) packet that triggers an LACP flap, resulting in denial of service and traffic loss.

MitigationUpgrade Junos OS to a fixed version (20.4R3-S8 or later, 21.2R3-S6 or later, 21.4R3-S4 or later, 22.1R3-S3 or later, 22.2R3-S1 or later, 22.3R2-S2/22.3R3 or later, 22.4R2-S1/22.4R3 or later). If immediate upgrade is not possible, consider network segmentation to limit adjacent attacker access to affected interfaces.

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:= 20.4= 21.2= 21.4= 22.1= 22.2= 22.3= 22.4

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/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. Identify device model
    Run 'show chassis hardware' or 'show system information' to determine the hardware model
    Affected if Device is a QFX5000 Series switch, EX4400, EX4100, or EX4650
  2. Check Junos OS version
    Run 'show version' to obtain the installed Junos OS version
    Affected if Version is 20.4, 21.2, 21.4, 22.1, 22.2, 22.3, or 22.4 (any sub-version within these releases)
  3. Verify LACP is enabled
    Run 'show lacp interfaces' or 'show configuration | match lacp' to check if Link Aggregation Control Protocol is configured on any interfaces
    Affected if LACP is configured and operational on one or more interfaces
  4. Assess network accessibility
    Review network topology and access controls to determine if an adjacent ( Layer 2 adjacent) attacker could reach the affected interfaces
    Affected if Interfaces with LACP are accessible to untrusted adjacent network segments

You are affected if your device is a QFX5000/EX4400/EX4100/EX4650 running a vulnerable Junos version (20.4, 21.2, 21.4, 22.1, 22.2, 22.3, or 22.4) with LACP enabled on interfaces that are reachable by an adjacent attacker.

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 a fixed version (20.4R3-S8 or later, 21.2R3-S6 or later, 21.4R3-S4 or later, 22.1R3-S3 or later, 22.2R3-S1 or later, 22.3R2-S2/22.3R3 or later, 22.4R2-S1/22.4R3 or later). If immediate upgrade is not possible, consider network segmentation to limit adjacent attacker access to affected interfaces.

Recommended fix High confidence

Upgrade to the first fixed version in your current branch: 20.4R3-S8, 21.2R3-S6, 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R3, or 22.4R3 (or respective S versions where noted)

  1. 1. Identify the currently running Junos OS version on the affected device using 'show version' command.
  2. 2. Determine which version branch your current installation belongs to (20.4R3, 21.2R3, 21.4R, 22.1R, 22.2R, 22.3R, or 22.4R).
  3. 3. Download the appropriate fixed version for your branch from the Juniper Networks support portal: for 20.4 branch use 20.4R3-S8 or later, for 21.2 branch use 21.2R3-S6 or later, for 21.4 branch use 21.4R3-S4 or later, for 22.1 branch use 22.1R3-S3 or later, for 22.2 branch use 22.2R3-S1 or later, for 22.3 branch use 22.3R3 or later, for 22.4 branch use 22.4R3 or later.
  4. 4. Upload the Junos OS upgrade package to the device using 'file copy' or USB transfer.
  5. 5. Perform the upgrade using 'request system software add <package> reboot' command.
  6. 6. After reboot, verify the new version is running with 'show version' and confirm the issue is resolved by testing LACP packet handling.
Caveat Standard Junos upgrade considerations apply - review release notes for compatibility, ensure configuration backup before upgrade, and plan for brief downtime during the upgrade process.

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
  • Testing4.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,380
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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-2024-30388 in production — separate from our analysis above.

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What this is

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