{"id":"CVE-2021-20609","aliases":["EUVD-2021-8027","GHSA-x5r4-fjpr-vr8v"],"status":"published","title":"Uncontrolled Resource Consumption vulnerability in MELSEC iQ-R Series R00/01/02CPU Firmware...","description":"Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. 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":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.03273,"percentile":0.88517,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-400"],"published":"2021-12-01T15:41:20Z","modified":"2026-06-17T03:34:06Z","products":[{"vendor":"mitsubishi","product":"melipc_mi5122-vw_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r00_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r01_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r02_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r04_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r04_pcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r08_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r08_pcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r08_sfcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r120_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r120_pcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r120_sfcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r12_ccpu-v_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r16_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r16_mtcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r16_pcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r16_sfcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r32_cpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r32_mtcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r32_pcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r32_sfcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_iq-r_r64_mtcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_l02cpu\\(-p\\)_firmware"},{"vendor":"mitsubishi","product":"melsec_l06cpu\\(-p\\)_firmware"},{"vendor":"mitsubishi","product":"melsec_l26cpu-\\(p\\)bt_firmware"},{"vendor":"mitsubishi","product":"melsec_l26cpu\\(-p\\)_firmware"},{"vendor":"mitsubishi","product":"melsec_mr-mq100_firmware"},{"vendor":"mitsubishi","product":"melsec_q03udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q03udvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q04udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q04udpvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q04udvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q06udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q06udpvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q06udvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q100udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q10udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q12dccpu-v_firmware"},{"vendor":"mitsubishi","product":"melsec_q13udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q13udpvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q13udvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q170mcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q170mscpu\\(-s1\\)_firmware"},{"vendor":"mitsubishi","product":"melsec_q172dcpu-s1_firmware"},{"vendor":"mitsubishi","product":"melsec_q172dscpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q173dcpu-s1_firmware"},{"vendor":"mitsubishi","product":"melsec_q173dscpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q20udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q24dhccpu-ls_firmware"},{"vendor":"mitsubishi","product":"melsec_q24dhccpu-v\\(g\\)_firmware"},{"vendor":"mitsubishi","product":"melsec_q26dhccpu-ls_firmware"},{"vendor":"mitsubishi","product":"melsec_q26udecpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q26udpvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q26udvcpu_firmware"},{"vendor":"mitsubishi","product":"melsec_q50udecpu_firmware"},{"vendor":"mitsubishi electric corporation","product":"melipc series mi5122-vw"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r00cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r01cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r02cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r04cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r04encpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r08cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r08encpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r08pcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r08psfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r08sfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r120cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r120encpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r120pcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r120psfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r120sfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r12ccpu-v"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16encpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16mtcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16pcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16psfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r16sfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32encpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32mtcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32pcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32psfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r32sfcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec iq-r series r64mtcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l02cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l02cpu-p"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l06cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l06cpu-p"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l26cpu"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l26cpu-bt"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l26cpu-p"},{"vendor":"mitsubishi electric corporation","product":"melsec l series l26cpu-pbt"},{"vendor":"mitsubishi electric corporation","product":"melsec q series mr-mq100"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q03udecpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q03udvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q04udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q04udpvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q04udvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q06udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q06udpvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q06udvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q100udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q10udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q12dccpu-v"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q13udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q13udpvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q13udvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q170mcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q170mscpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q170mscpu-s1"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q172dcpu-s1"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q172dscpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q173dcpu-s1"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q173dscpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q20udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q24dhccpu-ls"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q24dhccpu-v"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q24dhccpu-vg"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q26dhccpu-ls"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q26udehcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q26udpvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q26udvcpu"},{"vendor":"mitsubishi electric corporation","product":"melsec q series q50udehcpu"}],"references":[{"url":"https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-019_en.pdf","tags":["vendor-advisory","x_transferred","Vendor Advisory"]},{"url":"https://jvn.jp/vu/JVNVU94434051/index.html","tags":["government-resource","x_transferred","Third Party Advisory"]},{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-334-02","tags":["government-resource","x_transferred","Third Party Advisory","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20609"},{"url":"https://github.com/advisories/GHSA-x5r4-fjpr-vr8v"}],"sources":{"cve":[{"id":"CVE-2021-20609","description":"Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.","status":"published","published":"2021-12-01T15:41:20Z","modified":"2024-08-03T17:45:44.852Z","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":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:32:55.564736Z"}],"euvd":[{"id":"EUVD-2021-8027","description":"Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.","status":"published","published":"2021-12-01T15:41:20Z","modified":"2024-08-03T17:45:44Z","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"}],"updated_at":"2026-11-03T03:25:08.888273Z"}],"ghsa":[{"id":"GHSA-x5r4-fjpr-vr8v","title":"Uncontrolled Resource Consumption vulnerability in MELSEC iQ-R Series R00/01/02CPU Firmware...","description":"Uncontrolled Resource Consumption vulnerability in MELSEC iQ-R Series R00/01/02CPU Firmware versions \"24\" and prior, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU Firmware versions \"57\" and prior, MELSEC iQ-R Series R08/16/32/120SFCPU All versions, MELSEC iQ-R Series R08/16/32/120PCPU Firmware versions \"29\" and prior, MELSEC iQ-R Series R08/16/32/120PSFCPU All versions, MELSEC iQ-R Series R16/32/64MTCPU All versions, MELSEC iQ-R Series R12CCPU-V All versions, MELSEC Q Series Q03UDECPU All versions, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU All versions, MELSEC Q Series Q03/04/06/13/26UDVCPU The first 5 digits of serial No. \"23071\" and prior, MELSEC Q Series Q04/06/13/26UDPVCPU The first 5 digits of serial No. \"23071\" and prior, MELSEC Q Series Q12DCCPU-V All versions, MELSEC Q Series Q24DHCCPU-V(G) All versions, MELSEC Q Series Q24/26DHCCPU-LS All versions, MELSEC Q Series MR-MQ100 All versions, MELSEC Q Series Q172/173DCPU-S1 All versions, MELSEC Q Series Q172/172DSCPU All versions, MELSEC Q Series Q170MCPU All versions, MELSEC Q Series Q170MSCPU(-S1) All versions, MELSEC L Series L02/06/26CPU(-P) All versions, MELSEC L Series L26CPU-(P)BT All versions and MELIPC Series MI5122-VW All versions allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.","status":"published","published":"2021-12-02T00:00:37Z","modified":"2023-01-27T05:04:18Z","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"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:42:25.677567Z"}],"nvd":[{"id":"CVE-2021-20609","description":"Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.","status":"published","published":"2021-12-01T16:15:07.467Z","modified":"2026-06-17T03:34:06.547Z","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":"secondary"},{"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":7.8,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:07:01.811115Z"}]}}