CVE-2021-20612
CVE-2021-20612 is a high-severity vulnerability in Mitsubishielectric Fx3u-enet 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.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 7.8
- EPSS exploit prediction: 4% (88th percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Mitsubishielectric Fx3u-enet Firmware
- Published:
- Last modified:
Description
Lack of administrator control over security vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.14 and prior, FX3U-ENET-L Firmware version 1.14 and prior and FX3U-ENET-P502 Firmware version 1.14 and prior allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition in communication function of the product or other unspecified effects by sending specially crafted packets to an unnecessary opening of TCP port. Control by MELSEC-F series PLC is not affected by this vulnerability, but system reset is required for recovery.
Frequently asked questions
- What is CVE-2021-20612?
- Lack of administrator control over security vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.14 and prior, FX3U-ENET-L Firmware version 1.14 and prior and FX3U-ENET-P502 Firmware version 1.14 and prior allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition in communication function of the product or other unspecified effects by sending specially crafted packets to an unnecessary opening of TCP port. Control by MELSEC-F series PLC is not affected by this vulnerability, but system reset is required for recovery.
- How severe is CVE-2021-20612?
- CVE-2021-20612 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-2021-20612 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-20612?
- CVE-2021-20612 primarily affects Mitsubishielectric Fx3u-enet Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-20612?
- 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-2021-20612 published?
- CVE-2021-20612 was published on 2022-01-14 and last updated on 2026-06-17.
References
- https://jvn.jp/vu/JVNVU93268332/index.html
- https://www.cisa.gov/uscert/ics/advisories/icsa-22-013-01
- https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-023_en.pdf
Affected products (3)
- cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:*
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- CVE-2021-20613 — High (CVSS 7.5): Improper initialization vulnerability in MELSEC-F series FX3U-ENET Firmware version 1.16 and prior, FX3U-ENET-L…
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