CVE-2017-11770

Improper Certificate Validation

7.5 HighFix available

.NET Core 1.0, 1.1, and 2.0 allow an unauthenticated attacker to remotely cause a denial of service attack against a .NET Core web application by improperly parsing certificate data. A denial of service vulnerability exists when .NET Core improperly handles parsing certificate data, aka ".NET CORE Denial Of Service Vulnerability".

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

5.42%Down 8.3 points since Apr 14, 2021

What each source reports

NVD Score used 7.5

Record: CVE-2017-11770
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-295
Updated: 2026-11-02

CVE List No score

Record: CVE-2017-11770
Updated: 2026-11-02

EUVDEUVD-2022-1668 No score

Record: EUVD-2022-1668
Updated: 2026-11-03

GitHub AdvisoriesGHSA-7mfr-774f-w5r9 7.5

Improper Certificate Validation

Record: GHSA-7mfr-774f-w5r9
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-295
Updated: 2026-11-02

OSVGHSA-7mfr-774f-w5r9 7.5

Improper Certificate Validation

Record: GHSA-7mfr-774f-w5r9
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-295
Updated: 2026-11-02

OSVRHSA-2017:3248 5.9

Red Hat Security Advisory: .NET Core security update

Record: RHSA-2017:3248
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`System.Security.Cryptography.X509Certificates` NuGet	4.0.0 up to 4.1.2	4.1.2
`Microsoft.NETCore.App` NuGet	1.0.0 up to 2.0.3	2.0.3
`System.Security.Cryptography.X509Certificates` NuGet	4.0.0 up to 4.1.2, plus listed versions 4.1.04.1.0-rc2-240274.1.1	4.1.2
`Microsoft.NETCore.App` NuGet	1.0.0 up to 2.0.3, plus listed versions 1.0.11.0.101.0.111.0.121.0.13 Show 27 moreShow less 1.0.141.0.151.0.161.0.31.0.41.0.51.0.5-servicing-004880-001.0.71.0.81.0.91.1.01.1.0-preview1-001100-001.1.11.1.101.1.111.1.121.1.131.1.21.1.41.1.51.1.61.1.71.1.81.1.92.0.02.0.0-preview1-002111-002.0.0-preview2-25407-01	2.0.3
`rh-dotnetcore10-dotnetcore` Red Hat:rhel_dotnet:1.0::el7	before 0:1.0.8-1.el7	0:1.0.8-1.el7
`rh-dotnetcore10-dotnetcore-debuginfo` Red Hat:rhel_dotnet:1.0::el7	before 0:1.0.8-1.el7	0:1.0.8-1.el7
`rh-dotnetcore11-dotnetcore` Red Hat:rhel_dotnet:1.1::el7	before 0:1.1.5-1.el7	0:1.1.5-1.el7
`rh-dotnetcore11-dotnetcore-debuginfo` Red Hat:rhel_dotnet:1.1::el7	before 0:1.1.5-1.el7	0:1.1.5-1.el7
`rh-dotnet20-dotnet` Red Hat:rhel_dotnet:2.0::el7	before 0:2.0.3-4.el7	0:2.0.3-4.el7
`rh-dotnet20-dotnet-debuginfo` Red Hat:rhel_dotnet:2.0::el7	before 0:2.0.3-4.el7	0:2.0.3-4.el7
`rh-dotnet20-dotnet-host` Red Hat:rhel_dotnet:2.0::el7	before 0:2.0.3-4.el7	0:2.0.3-4.el7
`rh-dotnet20-dotnet-runtime-2.0` Red Hat:rhel_dotnet:2.0::el7	before 0:2.0.3-4.el7	0:2.0.3-4.el7
`rh-dotnet20-dotnet-sdk-2.0` Red Hat:rhel_dotnet:2.0::el7	before 0:2.0.3-4.el7	0:2.0.3-4.el7

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, products	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2017-11770 is a high vulnerability (CVSS 7.5) in Microsoft .net Core, published November 15, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 5.42%, the 92nd percentile. Fixed in System.Security.Cryptography.X509Certificates 4.1.2.

References

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