CVE-2024-21605

Control-plane service interruption via misrouted link-local traffic

Published Apr 12, 2024 · Updated Aug 9, 2024

Resource exposure in the Junos OS PFE on SRX 300 Series allows attackers on an adjacent network to interrupt control-plane services. The PFE forwards valid link-local traffic received on STP-blocked ports to the control plane instead of blocking it, causing excessive resource consumption. Attackers must reach an SRX 300 Series link at Layer 2; sustained consumption disrupts all control and management protocols.

CVSS severity7.1
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exposure in the Junos OS PFE on SRX 300 Series allows attackers on an adjacent network to interrupt control-plane services. The PFE forwards valid link-local traffic received on STP-blocked ports to the control plane instead of blocking it, causing excessive resource consumption. Attackers must reach an SRX 300 Series link at Layer 2; sustained consumption disrupts all control and management protocols.

The record

CVE
CVE-2024-21605
Published
Apr 12, 2024
Updated
Aug 9, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-668, T1498
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 9, 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=21.2R3-S3 <21.2R3-S6
  2. Affected versionversion=22.1R3 <22.1R3-S4
  3. Affected versionversion=22.2R2 <22.2R3-S2
  4. Affected versionversion=22.3R2 <22.3R3-S1
  5. Affected versionversion=22.4 <22.4R2-S2, 22.4R3
  6. Affected versionversion=23.2 <23.2R1-S1, 23.2R2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=21.2R3-S3 <21.2R3-S6; version=22.1R3 <22.1R3-S4; version=22.2R2 <22.2R3-S2; version=22.3R2 <22.3R3-S1; version=22.4 <22.4R2-S2, 22.4R3; version=23.2 <23.2R1-S1, 23.2R2

Published CVSS scores

6.5Juniper Networks, Inc.CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1Juniper Networks, Inc.CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1498Network 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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