{"id":"CVE-2021-34585","aliases":["EUVD-2021-21235","GHSA-rhmm-fwg9-r5m5"],"status":"published","title":"CODESYS V2 web server: crafted requests could trigger a pointer dereference with an invalid address (DoS)","description":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.","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":0.00903,"percentile":0.60083,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-252","CWE-754"],"published":"2021-10-26T09:55:48Z","modified":"2026-06-17T03:56:10Z","products":[{"vendor":"codesys","product":"codesys"},{"vendor":"codesys","product":"codesys v2"},{"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"},{"vendor":"wago","product":"750-823_firmware"},{"vendor":"wago","product":"750-829_firmware"},{"vendor":"wago","product":"750-831_firmware"},{"vendor":"wago","product":"750-832_firmware"},{"vendor":"wago","product":"750-852_firmware"},{"vendor":"wago","product":"750-862_firmware"},{"vendor":"wago","product":"750-880_firmware"},{"vendor":"wago","product":"750-881_firmware"},{"vendor":"wago","product":"750-882_firmware"},{"vendor":"wago","product":"750-885_firmware"},{"vendor":"wago","product":"750-889_firmware"},{"vendor":"wago","product":"750-890_firmware"},{"vendor":"wago","product":"750-891_firmware"},{"vendor":"wago","product":"750-893_firmware"}],"references":[{"url":"https://customers.codesys.com/index.php?eID=dumpFile\u0026t=f\u0026f=16876\u0026token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7\u0026download=","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://www.tenable.com/security/research/tra-2021-47","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34585"},{"url":"https://github.com/advisories/GHSA-rhmm-fwg9-r5m5"}],"sources":{"cve":[{"id":"CVE-2021-34585","title":"CODESYS V2 web server: crafted requests could trigger a pointer dereference with an invalid address (DoS)","description":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.","status":"published","published":"2021-10-26T09:55:48.273Z","modified":"2024-09-16T21:58:06.631Z","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-252"],"updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-21235","description":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.","status":"published","published":"2021-10-26T09:55:48Z","modified":"2024-09-16T21:58:06Z","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":"2026-11-03T00:55:06.714252Z"}],"ghsa":[{"id":"GHSA-rhmm-fwg9-r5m5","title":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser...","description":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.","status":"published","published":"2022-05-24T19:18:51Z","modified":"2025-08-15T21:32:19Z","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-252","CWE-754"],"updated_at":"2026-11-02T15:03:19.214105Z"}],"nvd":[{"id":"CVE-2021-34585","description":"In the CODESYS V2 web server prior to V1.1.9.22 crafted web server requests can trigger a parser error. Since the parser result is not checked under all conditions, a pointer dereference with an invalid address can occur. This leads to a denial of service situation.","status":"published","published":"2021-10-26T10:15:07.907Z","modified":"2026-06-17T03:56:10.827Z","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-252"],"updated_at":"2026-11-02T14:07:00.137719Z"}]}}