Home/CVE/A denial of service vulnerability exists when the ASP.NET Core fails to properly validate web requests. NOTE: Microsoft
CVE

CVE-2017-0247

A denial of service vulnerability exists when the ASP.NET Core fails to properly validate web requests. NOTE: Microsoft

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.

HIGH · CVSS 7.5 EPSS 0.11122
Act now
  • EPSS ≥ 0.10 - elevated exploitation probability
  • EPSS percentile: top 6% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-20Improper Input Validation
▤

Affected Products & Versions

9
microsoft asp.net model view controllerall versions
microsoft microsoft.aspnetcore.mvc.abstractionsall versions
microsoft microsoft.aspnetcore.mvc.apiexplorerall versions
microsoft microsoft.aspnetcore.mvc.corsall versions
microsoft microsoft.aspnetcore.mvc.dataannotationsall versions
microsoft microsoft.aspnetcore.mvc.formatters.jsonall versions
microsoft microsoft.aspnetcore.mvc.formatters.xmlall versions
microsoft microsoft.aspnetcore.mvc.localizationall versions
▤

Affected Packages

19
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
NuGet Microsoft.AspNetCore.Mvc HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Abstractions HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.ApiExplorer HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Core HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Cors HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.DataAnnotations HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Formatters.Json HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Formatters.Xml HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Localization HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Razor HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.Razor.Host HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.TagHelpers HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.ViewFeatures HIGH fixed in 1.0.4
NuGet Microsoft.AspNetCore.Mvc.WebApiCompatShim HIGH fixed in 1.0.4
NuGet System.Net.Http HIGH fixed in 4.1.2
NuGet System.Net.Http.WinHttpHandler HIGH fixed in 4.0.1
NuGet System.Net.Security HIGH fixed in 4.0.1
NuGet System.Net.WebSockets.Client HIGH fixed in 4.0.1
NuGet System.Text.Encodings.Web HIGH fixed in 4.0.1
⚠

Public Exploits & PoCs

1
pocwww.sidertia.com · ASPNET-Core-Unicode-Non-Char-Encoding-DoSwww.sidertia.com
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.0 · secure@microsoft.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD12 May 2017 · 02:29 PM
CVSS VectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/aspnet/Announcements/issues/239Technical DescriptionThird Party Advisory
https://technet.microsoft.com/en-us/library/security/4021279.aspxPatchVendor Advisory
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