CVE-2023-22403
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 · uneditedAn Allocation of Resources Without Limits or Throttling vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). On QFX10K Series, Inter-Chassis Control Protocol (ICCP) is used in MC-LAG topologies to exchange control information between the devices in the topology. ICCP connection flaps and sync issues will be observed due to excessive specific traffic to the local device. This issue affects Juniper Networks Junos OS on QFX10K Series: * All versions prior to 20.2R3-S7; * 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; * 21.4 versions prior to 21.4R3; * 22.1 versions prior to 22.1R2.
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 confidenceA network-based, unauthenticated attacker can send excessive specific traffic to exploit an allocation of resources without limits vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10K Series devices. This causes resource exhaustion leading to Inter-Chassis Control Protocol (ICCP) connection flaps and sync issues in MC-LAG topologies, resulting in Denial of Service.
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< 20.2= 20.2= 20.4= 21.1= 21.2= 21.3= 21.4= 22.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify device modelRun 'show chassis hardware' or 'show version' to confirm the device is a QFX10K Series switchAffected if Device is NOT a QFX10K Series - vulnerability only affects QFX10K
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Check Junos OS versionRun 'show version' and note the Junos OS version numberAffected if Version matches: < 20.2, = 20.2, = 20.4, = 21.1, = 21.2, = 21.3, = 21.4, or = 22.1
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Verify MC-LAG configurationRun 'show configuration protocols lacp' and 'show configuration protocols iccp' to check for MC-LAG and Inter-Chassis Control Protocol settingsAffected if MC-LAG with ICCP is configured - vulnerability requires this topology to be exploitable
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Check for ICCP connection flapsRun 'show iccp' and look for connection failures, or review system logs for ICCP-related error messagesAffected if ICCP connections are flapping or showing sync failures - indicates possible exploitation
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Assess network exposureReview firewall filters and interface access controls to determine if the device PFE is reachable from untrusted networksAffected if Device is network-accessible to untrusted attackers - exploit requires sending specific traffic to the device
Affected if QFX10K Series device runs an affected Junos version AND has MC-LAG/ICCP configured AND is exposed to untrusted network paths where an attacker can send specific traffic to the PFE.
Generated from the published advisory. Verify against your own configuration.
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 · scoped20.2
Apply the appropriate Junos OS software update (20.2R3-S7, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, 21.4R3, or 22.1R2 or later depending on the current branch) to address the resource allocation vulnerability in the PFE.
Upgrade to Junos OS 22.1R2 or the latest available fixed release in your current branch (20.2R3-S7, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, or 21.4R3)
- 1. Identify the current Junos OS version on the QFX10K device using 'show version' command
- 2. Determine the appropriate upgrade path based on current version and compatibility requirements
- 3. Download the relevant fixed Junos OS image (20.2R3-S7, 20.4R3-S4, 21.1R3-S3, 21.2R3-S1, 21.3R3, 21.4R3, or 22.1R2) from the Juniper Networks support portal
- 4. Verify the software image integrity using checksums provided by Juniper
- 5. Upload the new Junos OS image to the device's /var/tmp directory
- 6. Validate the software package with 'request system software validate <package>' command
- 7. Install the software using 'request system software add <package>' command
- 8. Reboot the device to complete the upgrade using 'request system reboot' command
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2023-22403 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-22403 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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