A denial of service vulnerability exists when the ASP.NET Core fails to properly validate web requests.
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.
- Published
- May 12, 2017
- Updated
- Jun 16, 2026
- EPSS
- 16.9% · 97th percentile
- CWE
- CWE-20
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Report tools
Action score
35
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 5 / 30 · 16.9%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| microsoft | asp.net model view controller | cpe:2.3:a:microsoft:asp.net_model_view_controller |
| microsoft | microsoft.aspnetcore.mvc.abstractions | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.abstractions |
| microsoft | microsoft.aspnetcore.mvc.apiexplorer | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.apiexplorer |
| microsoft | microsoft.aspnetcore.mvc.cors | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.cors |
| microsoft | microsoft.aspnetcore.mvc.dataannotations | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.dataannotations |
| microsoft | microsoft.aspnetcore.mvc.formatters.json | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.formatters.json |
| microsoft | microsoft.aspnetcore.mvc.formatters.xml | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.formatters.xml |
| microsoft | microsoft.aspnetcore.mvc.localization | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.localization |
| microsoft | microsoft.aspnetcore.mvc.razor | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.razor |
| microsoft | microsoft.aspnetcore.mvc.razor.host | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.razor.host |
| microsoft | microsoft.aspnetcore.mvc.taghelpers | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.taghelpers |
| microsoft | microsoft.aspnetcore.mvc.viewfeatures | cpe:2.3:a:microsoft:microsoft.aspnetcore.mvc.viewfeatures |
and 6 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- microsoft asp.net model view controller1.0.0
- microsoft asp.net model view controller1.0.1
- microsoft asp.net model view controller1.0.2
- microsoft asp.net model view controller1.0.3
- microsoft asp.net model view controller1.1.0
- microsoft asp.net model view controller1.1.1
- microsoft asp.net model view controller1.1.2
- microsoft microsoft.aspnetcore.mvc.abstractions1.0.0
- microsoft microsoft.aspnetcore.mvc.abstractions1.0.1
- microsoft microsoft.aspnetcore.mvc.abstractions1.0.2
- microsoft microsoft.aspnetcore.mvc.abstractions1.0.3
- microsoft microsoft.aspnetcore.mvc.abstractions1.1.0
- microsoft microsoft.aspnetcore.mvc.abstractions1.1.1
- microsoft microsoft.aspnetcore.mvc.abstractions1.1.2
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.0.0
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.0.1
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.0.2
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.0.3
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.1.0
- microsoft microsoft.aspnetcore.mvc.apiexplorer1.1.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.
Microsoft Corporation ASP.NET Core
- ASP.NET Coreaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| NuGet | Microsoft.AspNetCore.Mvc | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Abstractions | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Abstractions | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.ApiExplorer | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.ApiExplorer | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Core | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Core | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Cors | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Cors | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.DataAnnotations | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.DataAnnotations | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Formatters.Json | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Formatters.Json | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Formatters.Xml | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Formatters.Xml | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Localization | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Localization | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Razor | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Razor | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.Razor.Host | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.Razor.Host | from 1.1.0 · before 1.1.3 | 1.1.3 |
| NuGet | Microsoft.AspNetCore.Mvc.TagHelpers | from 1.0.0 · before 1.0.4 | 1.0.4 |
| NuGet | Microsoft.AspNetCore.Mvc.TagHelpers | from 1.1.0 · before 1.1.3 | 1.1.3 |
+14
Same product
microsoft: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-0249An elevation of privilege vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.30Monitor
- CVE-2014-4075Cross-site scripting (XSS) vulnerability in System.Web.Mvc.dll in Microsoft ASP.NET Model View Controller (MVC) 2.0 through 5.1 allows remot23Monitor
- CVE-2017-0256A spoofing vulnerability exists when the ASP.NET Core fails to properly sanitize web requests.22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| NuGet:Microsoft.AspNetCore.Mvc | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Abstractions | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Abstractions | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.ApiExplorer | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.ApiExplorer | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Core | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Core | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Cors | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Cors | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.DataAnnotations | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.DataAnnotations | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Formatters.Json | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Formatters.Json | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Formatters.Xml | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Formatters.Xml | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Localization | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Localization | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Razor | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Razor | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Razor.Host | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.Razor.Host | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.TagHelpers | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.TagHelpers | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.ViewFeatures | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.ViewFeatures | 1.1.3 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.WebApiCompatShim | 1.0.4 | Package registry (OSV) |
| NuGet:Microsoft.AspNetCore.Mvc.WebApiCompatShim | 1.1.3 | Package registry (OSV) |
| NuGet:System.Net.Http | 4.1.2 | Package registry (OSV) |
| NuGet:System.Net.Http | 4.3.2 | Package registry (OSV) |
+8
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.