CVE-2024-39533Network attack vector

Network filter bypass via unsupported output matches

Published Jul 11, 2024 · Updated Aug 2, 2024

Firewall-filter bypass in Juniper Networks Junos OS allows remote attackers to send traffic past intended output filtering. On QFX5000 and EX4600 switches, commit logic accepts ip-source-address, ip-destination-address, or arp-type in an output ethernet-switching filter even though those matches are unsupported, leaving the filter unapplied. Exploitation requires such a committed output filter and traffic matching its intended restriction; affected downstream traffic passes without the configured integrity control.

CVSS severity6.9
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Firewall-filter bypass in Juniper Networks Junos OS allows remote attackers to send traffic past intended output filtering. On QFX5000 and EX4600 switches, commit logic accepts ip-source-address, ip-destination-address, or arp-type in an output ethernet-switching filter even though those matches are unsupported, leaving the filter unapplied. Exploitation requires such a committed output filter and traffic matching its intended restriction; affected downstream traffic passes without the configured integrity control.

The record

CVE
CVE-2024-39533
Published
Jul 11, 2024
Updated
Aug 2, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-447, T1562.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <21.2r3-s7
  2. Affected versionversion=0 <21.2R3-S7
  3. Affected versionversion=21.4 <21.4r3-s6
  4. Affected versionversion=21.4 <21.4R3-S6
  5. Affected versionversion=22.1 <221r3--s5
  6. Affected versionversion=22.1 <22.1R3-S5
  7. Affected versionversion=22.2 <22.2r3-s2
  8. Affected versionversion=22.2 <22.2R3-S3
  9. Affected versionversion=22.3 <22.3r3-s2
  10. Affected versionversion=22.3 <22.3R3-S2
  11. Affected versionversion=22.4 <22.4r3
  12. Affected versionversion=22.4 <22.4R3
  13. Affected versionversion=23.2 <23.2r2
  14. Affected versionversion=23.2 <23.2R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <21.2r3-s7; version=0 <21.2R3-S7; version=21.4 <21.4r3-s6; version=21.4 <21.4R3-S6; version=22.1 <221r3--s5; version=22.1 <22.1R3-S5; version=22.2 <22.2r3-s2; version=22.2 <22.2R3-S3; version=22.3 <22.3r3-s2; version=22.3 <22.3R3-S2; version=22.4 <22.4r3; version=22.4 <22.4R3; version=23.2 <23.2r2; version=23.2 <23.2R2

Published CVSS scores

6.9Juniper Networks, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
5.8Juniper Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

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-447Unimplemented or Unsupported Feature in UI
T1562.004Disable or Modify System Firewall

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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