CVE-2017-0247 ASP.NET Core fails to properly validate web requests
Remote attackers can cause a denial of service in ASP.NET Core applications by exploiting improper validation of Unicode characters in web requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-0247?
CVE-2017-0247 is a high-severity denial of service vulnerability in Microsoft Corporation ASP.NET Core, published on 12 May 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2017-0247?
40 open source packages ship an affected version, including Microsoft.AspNetCore.Mvc, Microsoft.AspNetCore.Mvc.Abstractions and Microsoft.AspNetCore.Mvc.ApiExplorer. It affects 18 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.AspNetCore.Mvc NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Abstractions NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Abstractions NuGet | From 1.0.0 | 1.0.4 |
34 more packages
Microsoft.AspNetCore.Mvc.Abstractions NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Abstractions NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.ApiExplorer NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.ApiExplorer NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.ApiExplorer NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.ApiExplorer NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Core NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Core NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Core NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Core NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Cors NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Cors NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Cors NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Cors NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.DataAnnotations NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.DataAnnotations NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.DataAnnotations NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.DataAnnotations NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Formatters.Json NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Formatters.Json NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Formatters.Json NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Formatters.Json NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Formatters.Xml NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Formatters.Xml NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Formatters.Xml NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Formatters.Xml NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Localization NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Localization NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Localization NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Localization NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Razor NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Razor NuGet | From 1.0.0 | 1.0.4 |
Microsoft.AspNetCore.Mvc.Razor NuGet | From 1.1.0 | 1.1.3 |
Microsoft.AspNetCore.Mvc.Razor NuGet | From 1.1.0 | 1.1.3 |
Products include 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 and 12 more.
How do I fix CVE-2017-0247?
Upgrade Microsoft.AspNetCore.Mvc to a fixed version for your release line: 1.0.4 or 1.1.3.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2017-0247 being exploited?
There is no known exploitation of CVE-2017-0247 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Corporation ASP.NET Core
Sources
Also known as ECHO-bc40-6686-bc02, GHSA-6xh7-4v2w-36q6.