CVE-2024-21586Network attack vector

Unauthenticated service interruption via PFE traffic handling

Published Jul 1, 2024 · Updated Aug 1, 2024

Improper condition handling in Juniper Networks Junos OS on SRX and NFX Series allows remote attackers to crash the PFE with valid traffic. The PFE mishandles undisclosed, valid traffic addressed to the device, causing its forwarding process to crash and automatically restart. No authentication is required, and repeated delivery sustains the service interruption.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper condition handling in Juniper Networks Junos OS on SRX and NFX Series allows remote attackers to crash the PFE with valid traffic. The PFE mishandles undisclosed, valid traffic addressed to the device, causing its forwarding process to crash and automatically restart. No authentication is required, and repeated delivery sustains the service interruption.

The record

CVE
CVE-2024-21586
Published
Jul 1, 2024
Updated
Aug 1, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-754, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 1, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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=0 <21.4r1
  2. Affected versionversion=21.4 <21.4r3-s7.9
  3. Affected versionversion=21.4 <21.4R3-S7.9
  4. Affected versionversion=21.4 <21.4R3-S8
  5. Affected versionversion=22.1
  6. Affected versionversion=22.1 <22.1r3-s5.3
  7. Affected versionversion=22.1 <22.1R3-S5.3
  8. Affected versionversion=22.2 <22.2r3-s4.11
  9. Affected versionversion=22.2 <22.2R3-S4.11
  10. Affected versionversion=22.2 <22.2R3-S5
  11. Affected versionversion=22.3 <22.3r3
  12. Affected versionversion=22.3 <22.3R3
  13. Affected versionversion=22.4 <22.4r3
  14. Affected versionversion=22.4 <22.4R3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <21.4r1; version=21.4 <21.4r3-s7.9; version=21.4 <21.4R3-S7.9; version=21.4 <21.4R3-S8; version=22.1; version=22.1 <22.1r3-s5.3; version=22.1 <22.1R3-S5.3; version=22.2 <22.2r3-s4.11; version=22.2 <22.2R3-S4.11; version=22.2 <22.2R3-S5; version=22.3 <22.3r3; version=22.3 <22.3R3; version=22.4 <22.4r3; version=22.4 <22.4R3

Published CVSS scores

7.5Juniper Networks, Inc.CVSS:3.1/AV:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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