CVE-2024-30410Network attack vector

Network filter bypass via reversed rule precedence

Published Apr 12, 2024 · Updated Aug 2, 2024

Incorrect behavior order in Junos OS on EX4300 switches allows remote attackers to bypass an IPv6 loopback firewall discard rule. The routing engine evaluates the revenue-interface firewall filter before the loopback filter, so device-bound traffic reaches the RE despite a discard term on lo0. Exposure requires an IPv6 firewall filter on an EX4300; the bypass permits unintended traffic to reach routing-engine services but does not itself disclose data or interrupt service.

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

What happened

Incorrect behavior order in Junos OS on EX4300 switches allows remote attackers to bypass an IPv6 loopback firewall discard rule. The routing engine evaluates the revenue-interface firewall filter before the loopback filter, so device-bound traffic reaches the RE despite a discard term on lo0. Exposure requires an IPv6 firewall filter on an EX4300; the bypass permits unintended traffic to reach routing-engine services but does not itself disclose data or interrupt service.

The record

CVE
CVE-2024-30410
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

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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 <20.4r3-s10
  2. Affected versionversion=0 <20.4R3-S10
  3. Affected versionversion=21.2 <21.2r3-s7
  4. Affected versionversion=21.2 <21.2R3-S7
  5. Affected versionversion=21.4 <21.4r3-s6
  6. Affected versionversion=21.4 <21.4R3-S6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <20.4r3-s10; version=0 <20.4R3-S10; version=21.2 <21.2r3-s7; version=21.2 <21.2R3-S7; version=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.

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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)
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

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Your stack

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