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JunosOperating system · Juniper

CVE-2023-22399

HIGH · 7.5 CVSS v3.1 Published 2023-01-13
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
When sFlow is enabled and it monitors a packet forwarded via ECMP, a buffer management vulnerability in the dcpfe process of Juniper Networks Junos OS on QFX10K Series systems allows an attacker to cause the Packet Forwarding Engine (PFE) to crash and restart by sending specific genuine packets to the device, resulting in a Denial of Service (DoS) condition. The dcpfe process tries to copy more data into a smaller buffer, which overflows and corrupts the buffer, causing a crash of the dcpfe process. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on QFX10K Series: All versions prior to 19.4R3-S9; 20.2 versions prior to 20.2R3-S6; 20.3 versions prior to 20.3R3-S6; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S2; 21.4 versions prior to 21.4R2-S2, 21.4R3; 22.1 versions prior to 22.1R2; 22.2 versions prior to 22.2R1-S2, 22.2R2.

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

Buffer overflow vulnerability in the dcpfe process on Juniper QFX10K Series switches where sFlow monitoring of ECMP-forwarded packets causes the PFE to crash due to a buffer copy operation exceeding buffer boundaries, resulting in repeatable DoS.

MitigationApply Juniper-supplied Junos OS patches for affected versions; consider disabling sFlow if not required, or implement network segmentation to limit exposure to untrusted traffic sources.

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:= 19.4= 20.2= 20.3= 20.4= 21.1= 21.2= 21.3= 21.4= 22.1= 22.2

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. Identify device model
    Run 'show chassis hardware' or 'show version' and locate the hardware model in the output
    Affected if Device is not a QFX10K Series switch (the vulnerability only affects QFX10K Series)
  2. Verify Junos version
    Run 'show version' and locate the Junos OS version string
    Affected if Version matches 19.4, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4, 22.1, or 22.2 (compare your installed version to these affected ranges)
  3. Confirm sFlow monitoring is enabled
    Run 'show protocols sflow' and check the output for sFlow configuration status
    Affected if sFlow is enabled and collecting samples (sFlow must be active for the buffer overflow to trigger)
  4. Check for ECMP routing configuration
    Run 'show routing-options forwarding-table' or 'show configuration routing-options' and look for ecmp-related settings
    Affected if ECMP (Equal-Cost Multipath) is configured and active (ECMP-forwarded packets are required to trigger the flaw)
  5. Inspect for dcpfe crash events
    Run 'show log messages' and search for recent dcpfe process crashes or PFE restart entries
    Affected if Recent dcpfe crashes or PFE restarts are logged, indicating potential exploitation

User is affected if they run a vulnerable Junos version (19.4, 20.2-20.4, 21.1-21.4, or 22.1-22.2) on QFX10K hardware with both sFlow monitoring and ECMP forwarding enabled.

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

Apply Juniper-supplied Junos OS patches for affected versions; consider disabling sFlow if not required, or implement network segmentation to limit exposure to untrusted traffic sources.

Recommended fix High confidence

Upgrade to the minimum fixed version for your current branch: 19.4R3-S9, 20.2R3-S6, 20.3R3-S6, 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S2, 21.4R3, 22.1R2, or 22.2R2 respectively. For example, if on 20.4 branch, upgrade to 20.4R3-S5 or later.

  1. 1. Identify the current Junos OS version running on the QFX10K Series device using 'show version'
  2. 2. Identify which branch (19.4, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4, 22.1, or 22.2) the current version belongs to
  3. 3. Download the appropriate fixed version for that branch from the Juniper Networks support portal
  4. 4. Upload the Junos OS upgrade package to the device
  5. 5. Install the upgrade using 'request system software add <package-name>' command
  6. 6. Reboot the device using 'request system reboot' command to apply the new software
  7. 7. After reboot, verify the new version is running with 'show version' and confirm sFlow functionality is working correctly
Caveat Review Juniper release notes for any known compatibility issues or new features that may affect your 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
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2023-22399 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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