{"cve":"CVE-2021-31340","nvd":{"published":"2021-06-08T20:15:08.853","modified":"2026-06-17T03:51:34.477","status":"Modified","description":"A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://cert-portal.siemens.com/productcert/pdf/ssa-787292.pdf","https://cert-portal.siemens.com/productcert/pdf/ssa-787292.pdf"],"products":["siemens:simatic_reader_rf610r_cmiit_firmware","siemens:simatic_reader_rf610r_etsi_firmware","siemens:simatic_reader_rf610r_fcc_firmware","siemens:simatic_reader_rf615r_cmiit_firmware","siemens:simatic_reader_rf615r_etsi_firmware","siemens:simatic_reader_rf615r_fcc_firmware","siemens:simatic_reader_rf650r_arib_firmware","siemens:simatic_reader_rf650r_cmiit_firmware","siemens:simatic_reader_rf650r_etsi_firmware","siemens:simatic_reader_rf650r_fcc_firmware","siemens:simatic_reader_rf680r_arib_firmware","siemens:simatic_reader_rf680r_cmiit_firmware","siemens:simatic_reader_rf680r_etsi_firmware","siemens:simatic_reader_rf680r_fcc_firmware","siemens:simatic_reader_rf685r_arib_firmware","siemens:simatic_reader_rf685r_cmiit_firmware","siemens:simatic_reader_rf685r_etsi_firmware","siemens:simatic_reader_rf685r_fcc_firmware","siemens:simatic_rf166c_firmware","siemens:simatic_rf185c_firmware","siemens:simatic_rf186c_firmware","siemens:simatic_rf186ci_firmware","siemens:simatic_rf188c_firmware","siemens:simatic_rf188ci_firmware","siemens:simatic_rf360r_firmware"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-31340","score":0.00988,"percentile":0.62479,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}