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JunosOperating system · Juniper

CVE-2024-30387

MEDIUM · 6.5 CVSS v3.1 Published 2024-04-12
Fix available
A fix is available. Upgrade to 20.4 or later.
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
A Missing Synchronization vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on ACX5448 and ACX710 allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). If an interface flaps while the system gathers statistics on that interface, two processes simultaneously access a shared resource which leads to a PFE crash and restart. This issue affects Junos OS: * All versions before 20.4R3-S9, * 21.2 versions before 21.2R3-S5,  * 21.3 versions before 21.3R3-S5,  * 21.4 versions before 21.4R3-S4, * 22.1 versions before 22.1R3-S2, * 22.2 versions before 22.2R3-S2, * 22.3 versions before 22.3R2-S2, 22.3R3, * 22.4 versions before 22.4R2.

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 race condition vulnerability in the Packet Forwarding Engine (PFE) of Juniper Junos OS on ACX5448 and ACX710 routers occurs when an interface flaps while the system collects statistics, causing two processes to simultaneously access a shared resource without proper synchronization, leading to PFE crash and restart.

MitigationUpgrade Junos OS on affected ACX5448 and ACX710 devices to the fixed version for your release branch (e.g., 20.4R3-S9, 21.2R3-S5, 21.3R3-S5, 21.4R3-S4, 22.1R3-S2, 22.2R3-S2, 22.3R2-S2/22.3R3, or 22.4R2 or later).

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= 20.4= 21.2= 21.3= 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. Confirm device model is affected
    Run 'show chassis hardware' or check the physical device label to verify the model is ACX5448 or ACX710
    Affected if The device is not an ACX5448 or ACX710 router (the vulnerability only affects these two models)
  2. Check installed Junos OS version
    Run 'show version' and note the exact Junos OS version string (e.g., 22.3R3, 21.4R3-S4)
    Affected if The installed version is any of: 20.4, 21.2, 21.3, 21.4, 22.1, 22.2, 22.3, 22.4, or any version below 20.4
  3. Compare version to fixed releases
    Cross-reference your version with the fixed branches: 20.4R3-S9 or later, 21.2R3-S5 or later, 21.3R3-S5 or later, 21.4R3-S4 or later, 22.1R3-S2 or later, 22.2R3-S2 or later, 22.3R3 or later, 22.4R2 or later
    Affected if Your version is earlier than the fixed release for your branch (e.g., 22.3R1 is vulnerable, 22.3R3 is fixed)
  4. Review PFE crash logs
    Run 'show log messages' and search for PFE crash indicators or examine 'show pfe statistics error' for abnormal restart counts
    Affected if PFE crashes or restarts have occurred, especially when interface flaps coincide with statistics collection

You are affected if you run Junos OS on an ACX5448 or ACX710 router at a vulnerable version (20.4 through 22.4 series) and have not upgraded to the patched release for your branch.

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
Upgrade available Upgrade to 20.4 or later
Fixed in 20.4
Interim mitigation

Upgrade Junos OS on affected ACX5448 and ACX710 devices to the fixed version for your release branch (e.g., 20.4R3-S9, 21.2R3-S5, 21.3R3-S5, 21.4R3-S4, 22.1R3-S2, 22.2R3-S2, 22.3R2-S2/22.3R3, or 22.4R2 or later).

Recommended fix High confidence

22.4R2 or later (or the S-level variant for your current branch: 20.4R3-S9, 21.2R3-S5, 21.3R3-S5, 21.4R3-S4, 22.1R3-S2, 22.2R3-S2, 22.3R2-S2 or 22.3R3)

  1. 1. Identify the current Junos OS version on the ACX5448 or ACX710 device using 'show version'
  2. 2. Determine the appropriate upgrade path based on current version (upgrade to a fixed release listed below)
  3. 3. Schedule a maintenance window as the upgrade will require a system reboot
  4. 4. Back up the current configuration using 'request system configuration rescue save'
  5. 5. Download the appropriate Junos OS upgrade image from Juniper support portal
  6. 6. Upload the upgrade image to the device using 'request system software add <path_to_image>'
  7. 7. Reboot the device using 'request system reboot'
  8. 8. After reboot, verify the new version using 'show version' and confirm the PFE is operational
Caveat Standard Junos upgrade - requires maintenance window and reboot; review Juniper upgrade guide for specific version jump considerations

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

Fix this in Junos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2024-30387 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data