CVE-2023-38744

Denial-of-service (DoS) vulnerability due to improper validation of specified type of input issue exists in the built-in EtherNet/IP port of the CJ Series CJ2 CPU unit and the communication function of the CS/CJ Series EtherNet/IP unit. If an affected product receives a packet which is specially crafted by a remote unauthenticated attacker, the unit of the affected product may fall into a denial-of-service (DoS) condition. Affected products/versions are as follows: CJ2M CPU Unit CJ2M-CPU3[] Unit version of the built-in EtherNet/IP section Ver. 2.18 and earlier, CJ2H CPU Unit CJ2H-CPU6[]-EIP Unit version of the built-in EtherNet/IP section Ver. 3.04 and earlier, CS/CJ Series EtherNet/IP Unit CS1W-EIP21 V3.04 and earlier, and CS/CJ Series EtherNet/IP Unit CJ1W-EIP21 V3.04 and earlier.

Published: 2023-08-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-38744 is rated Moderate Risk (50.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.35%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-38744

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-30 0.30% 0.35% +0.05%
2 2026-04-28 0.24% 0.30% +0.06%
3 2025-11-21 — 0.24% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-38744

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-38744

Affected software / configurations for CVE-2023-38744

Vendor Product Version Raw CPE
omron cj2m-cpu35_firmware <= 2.18 cpe:2.3:o:omron:cj2m-cpu35_firmware:*:*:*:*:*:*:*:*
omron cj2m-cpu34_firmware <= 2.18 cpe:2.3:o:omron:cj2m-cpu34_firmware:*:*:*:*:*:*:*:*
omron cj2m-cpu33_firmware <= 2.18 cpe:2.3:o:omron:cj2m-cpu33_firmware:*:*:*:*:*:*:*:*
omron cj2m-cpu32_firmware <= 2.18 cpe:2.3:o:omron:cj2m-cpu32_firmware:*:*:*:*:*:*:*:*
omron cj2m-cpu31_firmware <= 2.18 cpe:2.3:o:omron:cj2m-cpu31_firmware:*:*:*:*:*:*:*:*
omron cj2h-cpu68-eip_firmware <= 3.04 cpe:2.3:o:omron:cj2h-cpu68-eip_firmware:*:*:*:*:*:*:*:*
omron cj2h-cpu67-eip_firmware <= 3.04 cpe:2.3:o:omron:cj2h-cpu67-eip_firmware:*:*:*:*:*:*:*:*
omron cj2h-cpu66-eip_firmware <= 3.04 cpe:2.3:o:omron:cj2h-cpu66-eip_firmware:*:*:*:*:*:*:*:*
omron cj2h-cpu65-eip_firmware <= 3.04 cpe:2.3:o:omron:cj2h-cpu65-eip_firmware:*:*:*:*:*:*:*:*
omron cj2h-cpu64-eip_firmware <= 3.04 cpe:2.3:o:omron:cj2h-cpu64-eip_firmware:*:*:*:*:*:*:*:*
omron cs1w-eip21_firmware <= 3.04 cpe:2.3:o:omron:cs1w-eip21_firmware:*:*:*:*:*:*:*:*
omron cj1w-eip21_firmware <= 3.04 cpe:2.3:o:omron:cj1w-eip21_firmware:*:*:*:*:*:*:*:*

References for CVE-2023-38744

cvelogic Threat Intelligence