{"id":"CVE-2021-34593","aliases":["EUVD-2021-21243","GHSA-mp42-p5v3-r5p6"],"status":"published","title":"CODESYS V2 runtime: unauthenticated invalid requests may result in denial-of-service","description":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.","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":"2026-11-11","score":0.02662,"percentile":0.859,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-755"],"published":"2021-10-26T09:55:51Z","modified":"2026-06-17T03:56:11Z","products":[{"vendor":"codesys","product":"codesys v2"},{"vendor":"codesys","product":"plcwinnt"},{"vendor":"codesys","product":"runtime_toolkit"},{"vendor":"wago","product":"750-8202_firmware"},{"vendor":"wago","product":"750-8203_firmware"},{"vendor":"wago","product":"750-8204_firmware"},{"vendor":"wago","product":"750-8206_firmware"},{"vendor":"wago","product":"750-8207_firmware"},{"vendor":"wago","product":"750-8208_firmware"},{"vendor":"wago","product":"750-8210_firmware"},{"vendor":"wago","product":"750-8211_firmware"},{"vendor":"wago","product":"750-8212_firmware"},{"vendor":"wago","product":"750-8213_firmware"},{"vendor":"wago","product":"750-8214_firmware"},{"vendor":"wago","product":"750-8216_firmware"},{"vendor":"wago","product":"750-8217_firmware"}],"references":[{"url":"https://customers.codesys.com/index.php?eID=dumpFile\u0026t=f\u0026f=16877\u0026token=8faab0fc1e069f4edfca5d5aba8146139f67a175\u0026download=","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"http://seclists.org/fulldisclosure/2021/Oct/64","tags":["mailing-list","x_refsource_FULLDISC","x_transferred","Mailing List","Third Party Advisory"]},{"url":"http://packetstormsecurity.com/files/164716/CODESYS-2.4.7.0-Denial-Of-Service.html","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","VDB Entry"]},{"url":"http://packetstormsecurity.com/files/165874/WAGO-750-8xxx-PLC-Denial-Of-Service-User-Enumeration.html","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34593"},{"url":"https://github.com/advisories/GHSA-mp42-p5v3-r5p6"}],"sources":{"cve":[{"id":"CVE-2021-34593","title":"CODESYS V2 runtime: unauthenticated invalid requests may result in denial-of-service","description":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.","status":"published","published":"2021-10-26T09:55:51.381Z","modified":"2024-09-17T04:10:03.625Z","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-755"],"updated_at":"2026-11-02T14:33:11.59359Z"}],"euvd":[{"id":"EUVD-2021-21243","description":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.","status":"published","published":"2021-10-26T09:55:51Z","modified":"2024-09-17T04:10:03Z","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":"2026-11-03T00:28:25.314109Z"}],"ghsa":[{"id":"GHSA-mp42-p5v3-r5p6","title":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56...","description":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.","status":"published","published":"2022-05-24T19:18:51Z","modified":"2023-01-30T05:03:00Z","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-755"],"updated_at":"2026-11-02T14:46:45.069338Z"}],"nvd":[{"id":"CVE-2021-34593","description":"In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.","status":"published","published":"2021-10-26T10:15:08.013Z","modified":"2026-06-17T03:56:11.963Z","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":"secondary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-755"],"updated_at":"2026-11-02T14:07:00.549994Z"}]}}