CVE-2022-22191

Service interruption via ARP-triggered PFE watchdog timeout

Published Apr 14, 2022 · Updated Sep 16, 2024

Denial of service in Juniper Networks Junos OS on EX4300 switches allows remote attackers on the local broadcast domain to restart the PFE. PFEMAN processing fails to withstand a flood of specific ARP traffic and reaches a watchdog timeout that crashes and restarts the Packet Forwarding Engine. Unauthenticated access to the same broadcast domain is sufficient; repeated packets sustain transit interruption, and an affected FPC can temporarily leave a Virtual Chassis.

CVSS severity6.5
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Juniper Networks Junos OS on EX4300 switches allows remote attackers on the local broadcast domain to restart the PFE. PFEMAN processing fails to withstand a flood of specific ARP traffic and reaches a watchdog timeout that crashes and restarts the Packet Forwarding Engine. Unauthenticated access to the same broadcast domain is sufficient; repeated packets sustain transit interruption, and an affected FPC can temporarily leave a Virtual Chassis.

The record

CVE
CVE-2022-22191
Published
Apr 14, 2022
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-410, T1498.001
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=18.4 <18.4R2-S10, 18.4R3-S11
  2. Affected versionversion=19.1 <19.1R3-S8
  3. Affected versionversion=19.2 <19.2R1-S9, 19.2R3-S4
  4. Affected versionversion=19.3 <19.3R3-S5
  5. Affected versionversion=19.4 <19.4R2-S6, 19.4R3-S7
  6. Affected versionversion=20.1 <20.1R3-S3
  7. Affected versionversion=20.2 <20.2R3-S3
  8. Affected versionversion=20.3 <20.3R3-S2
  9. Affected versionversion=20.4 <20.4R3-S1
  10. Affected versionversion=21.1 <21.1R3
  11. Affected versionversion=21.2 <21.2R2-S1, 21.2R3
  12. Affected versionversion=21.3 <21.3R1-S2, 21.3R2
  13. Affected versionversion=unspecified <15.1R7-S12

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=18.4 <18.4R2-S10, 18.4R3-S11; version=19.1 <19.1R3-S8; version=19.2 <19.2R1-S9, 19.2R3-S4; version=19.3 <19.3R3-S5; version=19.4 <19.4R2-S6, 19.4R3-S7; version=20.1 <20.1R3-S3; version=20.2 <20.2R3-S3; version=20.3 <20.3R3-S2; version=20.4 <20.4R3-S1; version=21.1 <21.1R3; version=21.2 <21.2R2-S1, 21.2R3; version=21.3 <21.3R1-S2, 21.3R2; version=unspecified <15.1R7-S12

Published CVSS scores

6.5Juniper NetworksCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-410Insufficient Resource Pool
T1498.001Network Denial of Service: Direct Network Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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