CVE-2023-36838

Traffic interruption via flowd out-of-bounds read

Published Jul 14, 2023 · Updated Oct 22, 2024

Out-of-bounds read in flowd in Juniper Networks Junos OS on SRX Series allows local users to crash traffic forwarding via a CLI command. Flowd performs an out-of-bounds read while processing an undisclosed low-privilege CLI command, then terminates and generates a core dump. An authenticated low-privilege account is required; flowd restarts after temporary traffic interruption, but repeated execution sustains the outage.

CVSS severity5.5
Medium
EPSS probability0.18%
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

Out-of-bounds read in flowd in Juniper Networks Junos OS on SRX Series allows local users to crash traffic forwarding via a CLI command. Flowd performs an out-of-bounds read while processing an undisclosed low-privilege CLI command, then terminates and generates a core dump. An authenticated low-privilege account is required; flowd restarts after temporary traffic interruption, but repeated execution sustains the outage.

The record

CVE
CVE-2023-36838
Published
Jul 14, 2023
Updated
Oct 22, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-125, T1499.004
Attack vector
local
Privileges
authenticated

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

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=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]
  2. Affected versionversion=20.4 <20.4R3-S6
  3. Affected versionversion=21.1 <21.1R3-S5
  4. Affected versionversion=21.2 <21.2R3-S4
  5. Affected versionversion=21.3 <21.3R3-S4
  6. Affected versionversion=21.4 <21.4R3-S3
  7. Affected versionversion=22.1 <22.1R3-S1
  8. Affected versionversion=22.2 <22.2R3
  9. Affected versionversion=22.3 <22.3R2
  10. Affected versionversion=22.4 <22.4R1-S1, 22.4R2
  11. Affected versionversion=unspecified <20.2R3-S7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Juniper Networks · Junos OSversion=20.3 <20.3* changes=[{"at":"20.3R1","status":"affected"}]; version=20.4 <20.4R3-S6; version=21.1 <21.1R3-S5; version=21.2 <21.2R3-S4; version=21.3 <21.3R3-S4; version=21.4 <21.4R3-S3; version=22.1 <22.1R3-S1; version=22.2 <22.2R3; version=22.3 <22.3R2; version=22.4 <22.4R1-S1, 22.4R2; version=unspecified <20.2R3-S7

Published CVSS scores

5.5Juniper Networks, Inc.CVSS:3.1/AV:L/AC:L/PR:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

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