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JunosOperating system · Juniper

CVE-2021-0230

HIGH · 7.5 CVSS v3.1 Published 2021-04-22
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
On Juniper Networks SRX Series devices with link aggregation (lag) configured, executing any operation that fetches Aggregated Ethernet (AE) interface statistics, including but not limited to SNMP GET requests, causes a slow kernel memory leak. If all the available memory is consumed, the traffic will be impacted and a reboot might be required. The following log can be seen if this issue happens. /kernel: rt_pfe_veto: Memory over consumed. Op 1 err 12, rtsm_id 0:-1, msg type 72 /kernel: rt_pfe_veto: free kmem_map memory = (20770816) curproc = kmd An administrator can use the following CLI command to monitor the status of memory consumption (ifstat bucket): user@device > show system virtual-memory no-forwarding | match ifstat Type InUse MemUse HighUse Limit Requests Limit Limit Size(s) ifstat 2588977 162708K - 19633958 <<<< user@device > show system virtual-memory no-forwarding | match ifstat Type InUse MemUse HighUse Limit Requests Limit Limit Size(s) ifstat 3021629 189749K - 22914415 <<<< This issue affects Juniper Networks Junos OS on SRX Series: 17.1 versions 17.1R3 and above prior to 17.3R3-S11; 17.4 versions prior to 17.4R3-S5; 18.2 versions prior to 18.2R3-S7, 18.2R3-S8; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R2-S7, 18.4R3-S6; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R1-S6; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R2, 20.1R3; 20.2 versions prior to 20.2R2-S2, 20.2R3; 20.3 versions prior to 20.3R1-S2, 20.3R2. This issue does not affect Juniper Networks Junos OS prior to 17.1R3.

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 kernel memory leak vulnerability in Juniper SRX Series devices with link aggregation (LAG) configured. Operations that fetch Aggregated Ethernet (AE) interface statistics—including SNMP GET requests—trigger an unbounded memory leak in the kernel. If memory exhaustion occurs, traffic impact occurs and device reboot may be required.

MitigationUpgrade Junos OS to the fixed versions specified in the advisory (17.3R3-S11, 17.4R3-S5, 18.2R3-S7/S8, 18.3R3-S4, 18.4R2-S7/18.4R3-S6, 19.1R3-S4, 19.2R1-S6, 19.3R3-S1, 19.4R3-S1, 20.1R2/R3, 20.2R2-S2/20.2R3, or 20.3R1-S2/20.3R2 depending on branch). Monitor memory consumption using the provided 'show system virtual-memory' command as a temporary diagnostic measure.

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:= 17.1= 17.2= 17.3= 17.4= 18.2= 18.3= 18.4= 19.1= 19.2= 19.3= 19.4= 20.1

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
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 check 'show system information' to confirm the device is an SRX Series model
    Affected if Device is not an SRX Series gateway
  2. Confirm Junos version
    Run 'show version' to obtain the installed Junos version
    Affected if Version matches 17.1 through 20.1 (any of the listed affected releases)
  3. Verify LAG configuration exists
    Run 'show interfaces ae* | display set' or 'show configuration interfaces ae*' to list Aggregated Ethernet interface configurations
    Affected if No AE (LAG) interfaces are configured in the active configuration
  4. Check if SNMP is enabled
    Run 'show configuration snmp' to see if SNMP is configured
    Affected if SNMP is enabled and the device has AE interfaces configured on an affected Junos version
  5. Monitor kernel memory usage
    Run 'show system virtual-memory' to observe kernel memory consumption patterns over time
    Affected if Memory usage shows continuous growth without recovery, especially when AE interface statistics are accessed via SNMP or CLI

Device is affected if it is an SRX Series with Junos 17.1-20.1, has Aggregated Ethernet (LAG) interfaces configured, and SNMP or other statistics queries are performed against those AE interfaces, causing unbounded kernel memory growth.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Junos OS to the fixed versions specified in the advisory (17.3R3-S11, 17.4R3-S5, 18.2R3-S7/S8, 18.3R3-S4, 18.4R2-S7/18.4R3-S6, 19.1R3-S4, 19.2R1-S6, 19.3R3-S1, 19.4R3-S1, 20.1R2/R3, 20.2R2-S2/20.2R3, or 20.3R1-S2/20.3R2 depending on branch). Monitor memory consumption using the provided 'show system virtual-memory' command as a temporary diagnostic measure.

Fix this in Junos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2021-0230 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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