How severe is CVE-2023-38744?

CVE-2023-38744 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-38744 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-38744?

CVE-2023-38744 primarily affects Omron Cj2m-cpu35 Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-38744?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-38744 published?

CVE-2023-38744 was published on 2023-08-03 and last updated on 2026-06-17.

CVE-2023-38744

CVE-2023-38744 is a high-severity vulnerability in Omron Cj2m-cpu35 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1284.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1284
Affected product: Omron Cj2m-cpu35 Firmware
Published: 2023-08-03
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2023-38744?: CVE-2023-38744 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-38744 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-38744?: CVE-2023-38744 primarily affects Omron Cj2m-cpu35 Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-38744?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-38744 published?: CVE-2023-38744 was published on 2023-08-03 and last updated on 2026-06-17.

References

Affected products (12)

cpe:2.3:o:omron:cj2m-cpu35_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2m-cpu34_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2m-cpu33_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2m-cpu32_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2m-cpu31_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2h-cpu68-eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2h-cpu67-eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2h-cpu66-eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2h-cpu65-eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj2h-cpu64-eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cs1w-eip21_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:omron:cj1w-eip21_firmware:*:*:*:*:*:*:*:*

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