CVE-2023-36834

Traffic-processing halt via packet-induced PPE loops

Published Jul 14, 2023 · Updated Oct 22, 2024

Denial of service in the PFE of Juniper Networks Junos OS on SRX 4600 and SRX 5000 Series allows attackers to stop traffic processing. A specific genuine packet makes one PPE enter a persistent processing loop; repeated packets disable additional PPEs until the PFE cannot forward traffic. The target must use L2 transparent mode, and recovery requires restarting the affected FPC after traffic processing halts.

CVSS severity6.5
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

Denial of service in the PFE of Juniper Networks Junos OS on SRX 4600 and SRX 5000 Series allows attackers to stop traffic processing. A specific genuine packet makes one PPE enter a persistent processing loop; repeated packets disable additional PPEs until the PFE cannot forward traffic. The target must use L2 transparent mode, and recovery requires restarting the affected FPC after traffic processing halts.

The record

CVE
CVE-2023-36834
Published
Jul 14, 2023
Updated
Oct 22, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-372, T1498
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 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=20.1 <20.1* changes=[{"at":"20.1R1","status":"affected"}]
  2. Affected versionversion=20.2 <20.2R3-S7
  3. Affected versionversion=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]
  4. Affected versionversion=20.4 <20.4R3-S7
  5. Affected versionversion=21.1 <21.1R3-S5
  6. Affected versionversion=21.2 <21.2R3-S3
  7. Affected versionversion=21.3 <21.3R3-S3
  8. Affected versionversion=21.4 <21.4R3-S1
  9. Affected versionversion=22.1 <22.1R3
  10. Affected versionversion=22.2 <22.2R2
  11. Affected versionversion=22.3 <22.3R1-S1, 22.3R2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=20.1 <20.1* changes=[{"at":"20.1R1","status":"affected"}]; version=20.2 <20.2R3-S7; version=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]; version=20.4 <20.4R3-S7; version=21.1 <21.1R3-S5; version=21.2 <21.2R3-S3; version=21.3 <21.3R3-S3; version=21.4 <21.4R3-S1; version=22.1 <22.1R3; version=22.2 <22.2R2; version=22.3 <22.3R1-S1, 22.3R2

Published CVSS scores

6.5Juniper NetworksCVSS:3.1/AV:A/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.

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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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-372Incomplete Internal State Distinction
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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