{"api_version":"1","generated_at":"2026-05-13T13:54:01+00:00","cve":"CVE-2021-33541","urls":{"html":"https://cve.report/CVE-2021-33541","api":"https://cve.report/api/cve/CVE-2021-33541.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-33541","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-33541"},"summary":{"title":"CVE-2021-33541","description":"Phoenix Contact Classic Line Controllers ILC1x0 and ILC1x1 in all versions/variants are affected by a Denial-of-Service vulnerability. The communication protocols and device access do not feature authentication measures. Remote attackers can use specially crafted IP packets to cause a denial of service on the PLC's network communication module. A successful attack stops all network communication. To restore the network connectivity the device needs to be restarted. The automation task is not affected.","state":"PUBLIC","assigner":"info@cert.vde.com","published_at":"2021-06-25 19:15:00","updated_at":"2021-07-02 00:11:00"},"problem_types":["CWE-770"],"metrics":[],"references":[{"url":"https://cert.vde.com/en-us/advisories/vde-2021-019","name":"https://cert.vde.com/en-us/advisories/vde-2021-019","refsource":"CONFIRM","tags":[],"title":"PHOENIX CONTACT : Security Advisory for ILC1x1 Industrial controllers — English (USA)","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-33541","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33541","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"LEGACY","value":"This vulnerability was discovered by the Industrial Control Security Laboratory of Qi An Xin Technology Group Inc. from China and reported to CERT@VDE. PHOENIX CONTACT thanks CERT@VDE for the coordination and support with this publication.","lang":""}],"nvd_cpes":[{"cve_year":"2021","cve_id":"33541","vulnerable":"-1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"h","cpe4":"phoenixcontact","cpe5":"ilc1x0","cpe6":"-","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"33541","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"phoenixcontact","cpe5":"ilc1x0_firmware","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"33541","vulnerable":"-1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"h","cpe4":"phoenixcontact","cpe5":"ilc1x1","cpe6":"-","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"33541","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"phoenixcontact","cpe5":"ilc1x1_firmware","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"info@cert.vde.com","DATE_PUBLIC":"2021-06-23T10:00:00.000Z","ID":"CVE-2021-33541","STATE":"PUBLIC","TITLE":"Phoenix Contact: ILC1x Industrial controllers affected by Denial-of-Service vulnerability"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"ILC1x","version":{"version_data":[{"version_affected":"=","version_name":"ILC1x0","version_value":"all variants"},{"version_affected":"=","version_name":"ILC1x1","version_value":"all variants"}]}}]},"vendor_name":"Phoenix Contact"}]}},"credit":[{"lang":"eng","value":"This vulnerability was discovered by the Industrial Control Security Laboratory of Qi An Xin Technology Group Inc. from China and reported to CERT@VDE. PHOENIX CONTACT thanks CERT@VDE for the coordination and support with this publication."}],"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Phoenix Contact Classic Line Controllers ILC1x0 and ILC1x1 in all versions/variants are affected by a Denial-of-Service vulnerability. The communication protocols and device access do not feature authentication measures. Remote attackers can use specially crafted IP packets to cause a denial of service on the PLC's network communication module. A successful attack stops all network communication. To restore the network connectivity the device needs to be restarted. The automation task is not affected."}]},"generator":{"engine":"Vulnogram 0.0.9"},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-770 Allocation of Resources Without Limits or Throttling"}]}]},"references":{"reference_data":[{"name":"https://cert.vde.com/en-us/advisories/vde-2021-019","refsource":"CONFIRM","url":"https://cert.vde.com/en-us/advisories/vde-2021-019"}]},"solution":[{"lang":"eng","value":"Temporary Fix / Mitigation\n\nPhoenix Contact recommends operating network-capable devices in closed networks or protected with a suitable firewall. For detailed information on our recommendations for measures to protect network-capable devices, please refer to the Phoenix Contact application note:\nMeasures to protect network-capable devices with Ethernet connection (https://dam-mdc.phoenixcontact.com/asset/156443151564/0a870ae433c19148b80bd760f3a1c1f2/107913_en_03.pdf)"}],"source":{"advisory":"VDE-2021-019","defect":["VDE-2021-019"],"discovery":"EXTERNAL"}},"nvd":{"publishedDate":"2021-06-25 19:15:00","lastModifiedDate":"2021-07-02 00:11:00","problem_types":["CWE-770"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:C","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"COMPLETE","baseScore":7.8},"severity":"HIGH","exploitabilityScore":10,"impactScore":6.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"AND","children":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:phoenixcontact:ilc1x0_firmware:*:*:*:*:*:*:*:*","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":false,"cpe23Uri":"cpe:2.3:h:phoenixcontact:ilc1x0:-:*:*:*:*:*:*:*","cpe_name":[]}]}],"cpe_match":[]},{"operator":"AND","children":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:phoenixcontact:ilc1x1_firmware:*:*:*:*:*:*:*:*","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":false,"cpe23Uri":"cpe:2.3:h:phoenixcontact:ilc1x1:-:*:*:*:*:*:*:*","cpe_name":[]}]}],"cpe_match":[]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"33541","Ordinal":"208948","Title":"CVE-2021-33541","CVE":"CVE-2021-33541","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"33541","Ordinal":"1","NoteData":"Phoenix Contact Classic Line Controllers ILC1x0 and ILC1x1 in all versions/variants are affected by a Denial-of-Service vulnerability. The communication protocols and device access do not feature authentication measures. Remote attackers can use specially crafted IP packets to cause a denial of service on the PLC's network communication module. A successful attack stops all network communication. To restore the network connectivity the device needs to be restarted. The automation task is not affected.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"33541","Ordinal":"2","NoteData":"2021-06-25","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"33541","Ordinal":"3","NoteData":"2021-06-25","Type":"Other","Title":"Modified"}]}}}