CVE-2017-0247
A denial of service vulnerability exists when the ASP.NET Core fails to properly validate web requests.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 16.9%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
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 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 16.91% probability · 97th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- 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
- secure@microsoft.com
EPSS 16.9% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/aspnet/Announcements/issues/239Technical Description, Third Party Advisory
- https://technet.microsoft.com/en-us/library/security/4021279.aspxPatch, Vendor Advisory
- https://www.sidertia.com/Home/Community/Blog/2017/05/18/ASPNET-Core-Unicode-Non-Char-Encoding-DoSExploit, Third Party Advisory
- https://github.com/aspnet/Announcements/issues/239Technical Description, Third Party Advisory
- https://technet.microsoft.com/en-us/library/security/4021279.aspxPatch, Vendor Advisory
- https://www.sidertia.com/Home/Community/Blog/2017/05/18/ASPNET-Core-Unicode-Non-Char-Encoding-DoSExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.