CVE-2024-30389Network attack vector

Egress filter bypass via misordered packet processing

Published Apr 12, 2024 · Updated Aug 2, 2024

Incorrect behavior order in the PFE of Juniper Networks Junos OS 21.4R1 through 21.4R3-S5 allows remote attackers to bypass egress filters. The PFE processes an output firewall filter in the wrong order, fails to recognize matching packets, and permits the traffic instead of applying the configured rule. The flaw is reachable without authentication only when an output filter is applied to an affected EX4300 interface, allowing prohibited traffic to reach downstream networks.

CVSS severity6.9
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect behavior order in the PFE of Juniper Networks Junos OS 21.4R1 through 21.4R3-S5 allows remote attackers to bypass egress filters. The PFE processes an output firewall filter in the wrong order, fails to recognize matching packets, and permits the traffic instead of applying the configured rule. The flaw is reachable without authentication only when an output filter is applied to an affected EX4300 interface, allowing prohibited traffic to reach downstream networks.

The record

CVE
CVE-2024-30389
Published
Apr 12, 2024
Updated
Aug 2, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-696
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 12, 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=21.4 <21.4r3-s6
  2. Affected versionversion=21.4 <21.4R3-S6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=21.4 <21.4r3-s6; version=21.4 <21.4R3-S6

Published CVSS scores

5.8Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
6.9Juniper NetworksCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA: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-696Incorrect Behavior Order

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo