{"id":"CVE-2021-20596","aliases":["EUVD-2021-8014","GHSA-wrr3-chw5-r88x"],"status":"published","title":"NULL Pointer Dereference in MELSEC-F Series FX3U-ENET firmware version 1.14 and prior, FX3U-ENET...","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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.02172,"percentile":0.82445,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-476"],"published":"2021-07-22T11:02:56Z","modified":"2026-06-17T03:34:05Z","products":[{"vendor":"mitsubishielectric","product":"fx3u-enet-l_firmware"},{"vendor":"mitsubishielectric","product":"fx3u-enet-p502_firmware"},{"vendor":"mitsubishielectric","product":"fx3u-enet_firmware"}],"references":[{"url":"https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-006_en.pdf","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://jvn.jp/vu/JVNVU94348759/index.html","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory"]},{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-201-01","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20596"},{"url":"https://github.com/advisories/GHSA-wrr3-chw5-r88x"}],"sources":{"cve":[{"id":"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.","status":"published","published":"2021-07-22T11:02:56Z","modified":"2024-08-03T17:45:44.834Z","updated_at":"2026-11-02T14:32:55.564736Z"}],"euvd":[{"id":"EUVD-2021-8014","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.","status":"published","published":"2021-07-22T11:02:56Z","modified":"2024-08-03T17:45:44Z","updated_at":"2026-11-03T03:25:08.888273Z"}],"ghsa":[{"id":"GHSA-wrr3-chw5-r88x","title":"NULL Pointer Dereference in MELSEC-F Series FX3U-ENET firmware version 1.14 and prior, FX3U-ENET...","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.","status":"published","published":"2022-05-24T19:09:02Z","modified":"2023-01-30T05:00:57Z","cwes":["CWE-476"],"updated_at":"2026-11-02T14:46:18.635114Z"}],"nvd":[{"id":"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.","status":"published","published":"2021-07-22T12:15:07.787Z","modified":"2026-06-17T03:34:05.433Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:06:56.185362Z"}]}}