How severe is CVE-2017-0248?

No CVSS score has been assigned to CVE-2017-0248 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2017-0248?

CVE-2017-0248 affects the following packages: Microsoft.AspNetCore.Mvc (NuGet), Microsoft.AspNetCore.Mvc (NuGet), Microsoft.AspNetCore.Mvc.Core (NuGet), Microsoft.AspNetCore.Mvc.Core (NuGet), System.Net.Http (NuGet), System.Net.Http (NuGet), System.Text.Encodings.Web (NuGet), System.Text.Encodings.Web (NuGet), and 30 more. Ecosystems affected: NuGet.

How do I fix CVE-2017-0248?

Update Microsoft.AspNetCore.Mvc to 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-0248 is resolved across your whole dependency graph.

How do I detect CVE-2017-0248 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.Mvc, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2017-0248 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2017-0248 actively exploited in the wild?

No public exploit code has been indexed for CVE-2017-0248 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2017-0248?

CVE-2017-0248 has an EPSS (Exploit Prediction Scoring System) score of 5.5%, placing it in the 93th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2017-0248?

CVE-2017-0248 is classified as CWE-295 (CWE-295). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2017-0248 published, and has it been updated?

CVE-2017-0248 was published on October 16, 2018 and was last updated on December 5, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

CVE-2017-0248 — Microsoft.AspNetCore.Mvc

CVE-2017-0248 is a CWE-295 vulnerability in Microsoft.AspNetCore.Mvc. A fix is available for Microsoft.AspNetCore.Mvc — see the affected versions and patch details below.

Moderate severity vulnerability that affects Microsoft.AspNetCore.Mvc and Microsoft.AspNetCore.Mvc.Core

Published

Oct 16, 2018

Updated

Dec 5, 2024

Affected

38 pkgs

Patched

38 / 38

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

5.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs93th percentile — riskier than 93% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

38 pkgs affected

.NETMicrosoft.AspNetCore.Mvc.NETMicrosoft.AspNetCore.Mvc.NETMicrosoft.AspNetCore.Mvc.Core.NETMicrosoft.AspNetCore.Mvc.Core.NETSystem.Net.Http.NETSystem.Net.Http.NETSystem.Text.Encodings.Web.NETSystem.Text.Encodings.Web+30 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

Microsoft .NET Framework 2.0, 3.5, 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2 and 4.7 allow an attacker to bypass Enhanced Security Usage taggings when they present a certificate that is invalid for a specific use, aka ".NET Security Feature Bypass Vulnerability."

Affected Packages

38 total 38 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.AspNetCore.Mvc`	≥ 1.0.0&&< 1.0.4	1.0.4`dotnet add package Microsoft.AspNetCore.Mvc --version 1.0.4`
.NETNuGet	`Microsoft.AspNetCore.Mvc`	≥ 1.1.0&&< 1.1.3	1.1.3`dotnet add package Microsoft.AspNetCore.Mvc --version 1.1.3`
.NETNuGet	`Microsoft.AspNetCore.Mvc.Core`	≥ 1.0.0&&< 1.0.4	1.0.4`dotnet add package Microsoft.AspNetCore.Mvc.Core --version 1.0.4`
.NETNuGet	`Microsoft.AspNetCore.Mvc.Core`	≥ 1.1.0&&< 1.1.3	1.1.3`dotnet add package Microsoft.AspNetCore.Mvc.Core --version 1.1.3`
.NETNuGet	`System.Net.Http`	≥ 4.1.1&&< 4.1.2	4.1.2`dotnet add package System.Net.Http --version 4.1.2`
.NETNuGet	`System.Net.Http`	≥ 4.3.1&&< 4.3.2	4.3.2`dotnet add package System.Net.Http --version 4.3.2`

Affected Products

1 product · 8 configurations

Application

.net frameworkmicrosoft

8 versions

2.03.53.5.14.5.24.64.6.14.6.24.7

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.Mvc, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.Mvc to 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-0248 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.