High severity7.5NVD Advisory· Published Jul 22, 2021· Updated Jun 17, 2026
CVE-2021-20596
CVE-2021-20596
Description
NULL Pointer Dereference 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 DoS condition in communication by sending specially crafted packets. Control by MELSEC-F series PLC is not affected and system reset is required for recovery.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
5- Range: <=1.14
- MELSEC-F Series/MELSEC-F Series FX3U-ENET firmwaredescription
- cpe:2.3:o:mitsubishielectric:fx3u-enet-l_firmware:*:*:*:*:*:*:*:*Range: <=1.14
- cpe:2.3:o:mitsubishielectric:fx3u-enet-p502_firmware:*:*:*:*:*:*:*:*Range: <=1.14
- cpe:2.3:o:mitsubishielectric:fx3u-enet_firmware:*:*:*:*:*:*:*:*Range: <=1.14
Patches
Vulnerability mechanics
References
3- jvn.jp/vu/JVNVU94348759/index.htmlnvdPatchThird Party Advisory
- www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-006_en.pdfnvdPatchVendor Advisory
- us-cert.cisa.gov/ics/advisories/icsa-21-201-01nvdThird Party Advisory
News mentions
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