{"cve":"CVE-2017-0247","nvd":{"published":"2017-05-12T14:29:03.910","modified":"2026-06-17T00:57:20.260","status":"Modified","description":"A denial of service vulnerability exists when the ASP.NET Core fails to properly validate web requests. NOTE: Microsoft has not commented on third-party claims that the issue is that the TextEncoder.EncodeCore function in the System.Text.Encodings.Web package in ASP.NET Core Mvc before 1.0.4 and 1.1.x before 1.1.3 allows remote attackers to cause a denial of service by leveraging failure to properly calculate the length of 4-byte characters in the Unicode Non-Character range.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-20"],"references":["https://github.com/aspnet/Announcements/issues/239","https://technet.microsoft.com/en-us/library/security/4021279.aspx","https://www.sidertia.com/Home/Community/Blog/2017/05/18/ASPNET-Core-Unicode-Non-Char-Encoding-DoS","https://github.com/aspnet/Announcements/issues/239","https://technet.microsoft.com/en-us/library/security/4021279.aspx"],"products":["microsoft:asp.net_model_view_controller","microsoft:microsoft.aspnetcore.mvc.abstractions","microsoft:microsoft.aspnetcore.mvc.apiexplorer","microsoft:microsoft.aspnetcore.mvc.cors","microsoft:microsoft.aspnetcore.mvc.dataannotations","microsoft:microsoft.aspnetcore.mvc.formatters.json","microsoft:microsoft.aspnetcore.mvc.formatters.xml","microsoft:microsoft.aspnetcore.mvc.localization","microsoft:microsoft.aspnetcore.mvc.razor","microsoft:microsoft.aspnetcore.mvc.razor.host","microsoft:microsoft.aspnetcore.mvc.taghelpers","microsoft:microsoft.aspnetcore.mvc.viewfeatures","microsoft:microsoft.aspnetcore.mvc.webapicompatshim","microsoft:system.net.http","microsoft:system.net.http.winhttphandler","microsoft:system.net.security","microsoft:system.net.websockets.client","microsoft:system.text.encodings.web"],"source":"nvd","synced_at":"2026-10-19T20:42:36.429588156+00:00"},"epss":{"cve":"CVE-2017-0247","score":0.16911,"percentile":0.97055,"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."]}