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JunosOperating system · Juniper

CVE-2023-22396

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
An Uncontrolled Resource Consumption vulnerability in TCP processing on the Routing Engine (RE) of Juniper Networks Junos OS allows an unauthenticated network-based attacker to send crafted TCP packets destined to the device, resulting in an MBUF leak that ultimately leads to a Denial of Service (DoS). The system does not recover automatically and must be manually restarted to restore service. This issue occurs when crafted TCP packets are sent directly to a configured IPv4 or IPv6 interface on the device. Transit traffic will not trigger this issue. MBUF usage can be monitored through the use of the 'show system buffers' command. For example: user@junos> show system buffers | refresh 5 4054/566/4620 mbufs in use (current/cache/total) ... 4089/531/4620 mbufs in use (current/cache/total) ... 4151/589/4740 mbufs in use (current/cache/total) ... 4213/527/4740 mbufs in use (current/cache/total) This issue affects Juniper Networks Junos OS: 12.3 version 12.3R12-S19 and later versions; 15.1 version 15.1R7-S10 and later versions; 17.3 version 17.3R3-S12 and later versions; 18.4 version 18.4R3-S9 and later versions; 19.1 version 19.1R3-S7 and later versions; 19.2 version 19.2R3-S3 and later versions; 19.3 version 19.3R2-S7, 19.3R3-S3 and later versions prior to 19.3R3-S7; 19.4 version 19.4R2-S7, 19.4R3-S5 and later versions prior to 19.4R3-S10; 20.1 version 20.1R3-S1 and later versions; 20.2 version 20.2R3-S2 and later versions prior to 20.2R3-S6; 20.3 version 20.3R3-S1 and later versions prior to 20.3R3-S6; 20.4 version 20.4R2-S2, 20.4R3 and later versions prior to 20.4R3-S5; 21.1 version 21.1R2 and later versions prior to 21.1R3-S4; 21.2 version 21.2R1-S1, 21.2R2 and later versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S2; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R2-S1, 22.1R3; 22.2 versions prior to 22.2R1-S2, 22.2R2; 22.3 versions prior to 22.3R1-S1, 22.3R2.

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

An unauthenticated attacker can send specially crafted TCP packets directly to a configured IPv4/IPv6 interface on Juniper Networks Junos OS devices, causing an MBUF (memory buffer) leak in the Routing Engine. This leak exhausts system resources and results in a Denial of Service condition that requires manual device restart to recover. Transit traffic does not trigger this vulnerability - packets must be destined directly to the device.

MitigationApply the appropriate Junos OS software upgrade to a fixed version as listed in the Juniper advisory. During patching, monitor MBUF usage via 'show system buffers' and ensure a maintenance window with console access for potential recovery. Network-based ACLs can be deployed as a temporary mitigation to limit direct access to device management 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:= 12.3= 15.1= 17.3= 18.4= 19.1= 19.2= 19.3= 19.4= 20.1= 20.2= 20.3= 20.4

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
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 the Junos OS version
    Run 'show version' or 'show version detail' to obtain the installed Junos OS version
    Affected if The version matches one of the affected releases: 12.3, 15.1, 17.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1, 20.2, 20.3, or 20.4
  2. Confirm direct IP interface availability
    Run 'show interfaces terse' or 'show ip interface brief' to list directly configured IPv4/IPv6 addresses on device interfaces
    Affected if Any interface has a direct IPv4 or IPv6 address assigned (excluding loopback) that is reachable from untrusted networks
  3. Check current MBUF usage
    Run 'show system buffers' to display current memory buffer utilization
    Affected if The MBUF usage shows abnormally high consumption or approaching exhaustion limits, indicating a potential active leak
  4. Review interface management access
    Run 'show configuration system services' and 'show configuration interfaces' to identify enabled management protocols and interface configurations
    Affected if Management services such as telnet, SSH, or other IP-based services are enabled on directly accessible interfaces

The device is affected if it runs an affected Junos OS version AND has directly reachable IPv4/IPv6 interfaces, regardless of current MBUF state, since exploitation requires only network access to those interfaces.

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 the appropriate Junos OS software upgrade to a fixed version as listed in the Juniper advisory. During patching, monitor MBUF usage via 'show system buffers' and ensure a maintenance window with console access for potential recovery. Network-based ACLs can be deployed as a temporary mitigation to limit direct access to device management interfaces.

Recommended fix High confidence

Upgrade to the earliest fixed version for your release train (e.g., 12.3R12-S19, 15.1R7-S10, 17.3R3-S12, 18.4R3-S9) or migrate to a stable release branch like 19.4R3-S10, 20.4R3-S5, 21.4R3, or 22.3R2

  1. Identify the currently installed Junos OS version using 'show version'
  2. Consult the Junos upgrade matrix to determine the recommended upgrade path for your hardware platform
  3. Plan maintenance window as the device will require a reboot
  4. Back up current configuration using 'request system configuration rescue save'
  5. Upgrade to a fixed version: for 12.3 go to 12.3R12-S19 or later; for 15.1 go to 15.1R7-S10 or later; for 17.3 go to 17.3R3-S12 or later; for 18.4 go to 18.4R3-S9 or later
  6. Alternatively, upgrade to 19.4R3-S10 or later, 20.4R3-S5 or later, 21.4R3 or later, 22.1R2-S1 or later, 22.2R1-S2 or later, or 22.3R1-S1 or later for broader fixes
  7. After upgrade, verify MBUF consumption stabilizes using 'show system buffers'
Caveat Standard Junos upgrade considerations apply—review release notes for hardware compatibility and ensure configuration compatibility before upgrading

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

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,800
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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-2023-22396 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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