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JunosOperating system · Juniper

CVE-2023-22405

MEDIUM · 6.5 CVSS v3.1 Published 2023-01-13
Fix available
A fix is available. Upgrade to 20.2 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
An Improper Preservation of Consistency Between Independent Representations of Shared State vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause a Denial of Service (DoS) to device due to out of resources. When a device is configured with "service-provider/SP style" switching, and mac-limiting is configured on an Aggregated Ethernet (ae) interface, and then a PFE is restarted or the device is rebooted, mac-limiting doesn't work anymore. Please note that the issue might not be apparent as traffic will continue to flow through the device although the mac table and respective logs will indicate that mac limit is reached. Functionality can be restored by removing and re-adding the MAC limit configuration. This issue affects Juniper Networks Junos OS on QFX5k Series, EX46xx Series: All versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S5; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S3; 21.2 versions prior to 21.2R3-S1; 21.3 versions prior to 21.3R3 on; 21.4 versions prior to 21.4R3 on; 22.1 versions prior to 22.1R2 on.

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 Juniper Junos OS on QFX5k and EX46xx Series allows an adjacent attacker to cause DoS via resource exhaustion. When 'service-provider/SP style' switching with MAC-limiting is configured on an aggregated Ethernet interface, the PFE loses MAC-limiting functionality after restart or reboot - the MAC table shows the limit is reached but traffic continues flowing unrestricted due to inconsistent state between PFE and control plane representations.

MitigationUpgrade to fixed Junos OS versions (20.2R3-S5, 20.3R3-S5, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, 21.4R3, 22.1R2 or later). As a workaround, remove and re-add MAC limit configuration after each PFE restart or reboot to restore functionality.

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:< 20.2= 20.2= 20.3= 20.4= 21.1= 21.2= 21.3= 21.4= 22.1

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 check the device model. This vulnerability affects only QFX5k Series and EX46xx Series switches.
    Affected if Device is not a QFX5k or EX46xx Series model, then it is NOT affected by this CVE.
  2. Check Junos OS version
    Run 'show version' and compare the installed Junos version against the affected list: versions < 20.2, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4, and 22.1.
    Affected if The installed Junos version matches any of these affected versions.
  3. Verify service-provider switching style is configured
    Run 'show configuration switch-options' and look for 'service-provider' or 'sp' style switching configuration.
    Affected if Service-provider or SP style switching is configured in the switch-options.
  4. Check for MAC-limiting on aggregated Ethernet interfaces
    Run 'show configuration interfaces ae*' and look for 'mac-limit' configuration under the interface. Alternatively, run 'show ethernet-switching table mac-limit' to view current MAC limit settings.
    Affected if Aggregated Ethernet interfaces (ae*) have MAC-limiting configured.
  5. Verify MAC limit behavior after restart
    After a PFE restart or reboot, run 'show ethernet-switching table' to check if the MAC limit shows as reached, then verify if traffic continues to flow unrestricted through the interface despite the limit being shown as reached.
    Affected if MAC table shows limit reached but traffic continues to pass through the interface, indicating the vulnerability is present.

A user is affected if they run a vulnerable Junos version on QFX5k or EX46xx hardware with service-provider switching style and MAC-limiting configured on aggregated Ethernet, and observe that after a restart the MAC limit appears reached but traffic still flows unrestricted.

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 20.2 or later
Fixed in 20.2
Interim mitigation

Upgrade to fixed Junos OS versions (20.2R3-S5, 20.3R3-S5, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, 21.4R3, 22.1R2 or later). As a workaround, remove and re-add MAC limit configuration after each PFE restart or reboot to restore functionality.

Recommended fix High confidence

20.2R3-S5, 20.3R3-S5, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, 21.4R3, or 22.1R2 (depending on current version branch)

  1. Identify the current Junos OS version running on the device using 'show version'
  2. Determine the appropriate fixed release based on the current version: 20.2R3-S5 or later for 20.2 train, 20.3R3-S5 or later for 20.3 train, 20.4R3-S4 or later for 20.4 train, or the equivalent fixed releases for 21.x and 22.x trains
  3. Download the appropriate upgrade package from the Juniper Networks support portal (kb.juniper.net)
  4. Upload the upgrade package to the device using 'file copy' or similar method
  5. Initiate the upgrade using 'request system software add <package-name>' command
  6. Reboot the device to apply the changes using 'request system reboot'
  7. After reboot, verify the new version is installed using 'show version'
  8. If applicable, re-apply the MAC limit configuration to ensure proper functionality
Caveat Review Juniper upgrade guidelines for compatibility with other installed modules and ensure proper backup of configuration 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
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
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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-2023-22405 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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