CVE-2017-11770: .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

Ecosystem and package	Affected range	First fixed version	Evidence
NuGetMicrosoft.NETCore.App	`ECOSYSTEM: introduced 1.0.0; fixed 2.0.3`	`2.0.3`	OSV record ↗aggregator derived · 8 Nov 2023
NuGetSystem.Security.Cryptography.X509Certificates	`ECOSYSTEM: introduced 4.0.0; fixed 4.1.2`	`4.1.2`	OSV record ↗aggregator derived · 8 Nov 2023

Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available

What, why and how

.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".

What

Why

The product does not validate, or incorrectly validates, a certificate.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Why

The product does not validate, or incorrectly validates, a certificate.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: a network path → Improper Certificate Validation → disrupt the affected service
Attack surface: Network
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-295 ↗
CWE-295: Improper Certificate Validation. The product does not validate, or incorrectly validates, a certificate.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Vulnerability Scoring System 3.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

NetworkUnauthenticatedDenial of serviceCWE-295

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2022-1668Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

CERT-FR · French · CERTFR-2017-AVI-410Multiples vulnérabilités dans Microsoft .Net

De multiples vulnérabilités ont été corrigées dans Microsoft .Net . Elles permettent à un attaquant de provoquer une divulgation d'informations, une élévation de privilèges et un déni de service

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2017-010105.NET Core におけるサービス運用妨害 (DoS) の脆弱性

.NET Core は、証明書のデータを適切に構文解析しないため、サービス運用妨害 (DoS) 状態にされる脆弱性が存在します。ベンダは、本脆弱性を「.NET CORE Denial Of Service Vulnerability」として公開しています。

Official advisory ↗

KISA KrCERT/CC · Korean · KNVD-4816MS 11월 보안 위협에 따른 정기 보안 업데이트 권고

62047, 4011197, 4011199, 4011205, 4011206, 4011220, 4011233, 4011242, 4011245, 4011247, 4011250, 4011262, 4011264, 4011265, 4011266, 4011267, 4011268, 4011270, 4011271, 4011276 ##### □ 해결책 o 영향 받는 소프트웨어를 이용하는 경우 마이크로소프트사의 보안 패치 적용 SharePoint Enterprise Server 2016, Project Server 2013 보안 업데이트 ##### □ 설명 o 이용자가 특수 제작된 악성 웹 페이지를 방문할 경우, 접근 제한이 있는 콘텐츠 열람과 같은 권한상승이 허용되는 취약점 o 관련취약점 : - 권한상승 취약점(CVE-2017-11876) o 영향 : 권한상승 o 중요도 : 보통 o 관련 KB 번호 - 4011244, 4011257 ##### □ 해결책 o 영향 받는 소프트웨어를 이용하는 경우 마이크로소프트사의 보안 패치 적용 .NET Core, ASP.NET Core 보안 업데이트 ##### □ 설명 o 이용자가 특수 제작된 악성 웹 페이지 링크를 클릭할 경우, 쿠키 및 인증 토큰 탈취로 인해 권한상승이 허용되는 취약점 o 관련취약점 : - 서비스거부 취약점(CVE-2017-11770, 11883) - 권한상승 취약점(CVE-2017-11879) - 정보노출 취약점(CVE-2017-8700) o 영향 : 권한상승 o 중요도 : 중요 ##### □ 해결책 o 영향 받는 소프트웨어를 이용하는 경우 마이크로소프트사의 보안 패치 적용 [참고사이트] [1] https://github.com/aspnet/announcements/issues/277 [2] https://github.com/aspnet/announcements/issues/278 [3] https://github.com/dotnet/announcements/pull/40 ChakraCore 보안 업데이트 ##### □ 설명 o 이용자가 Edge로 특수하게 제작된 악성 웹 페이지를 열람할 경우, 원격코드실행이 허용되는 취약점 ※ ChakraCore : Edge의 자바스크립트 엔진, Cloud, 게임엔진, IoT 등에서도 사용 o 관련취약점 : - 정보노출 취약점(CVE-2017-11791) - 원격코드실행 취약점(CVE-2017-11836, 11837, 11838, 11840, 11841, 11843, 11846, 11858, 11861, 11862, 11866, 11870, 11871, 11873) - 보안기능 우회 취약점(CVE-2017-11874) o 영향 : 원격코

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Patch available
Affected: .NET Core: .NET Core 1.0, .NET Core 1.1, and .NET Core 2.0
Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action: Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround: No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.

Evidence and provenance

Published 15 Nov 2017 · Last source change 16 Sept 2024, 22:41 UTC · CWE-295 · Improper Certificate Validation

CVE recordCVE.org · 5.1

CVSS sourceNIST NVD

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-09-01

European sourceENISA EUVD · EUVD-2022-1668

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceNIST NVD

NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

1 Sep 2026, 02:42 UTC
ENISA EUVD mappingEUVD-2022-1668 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2022-1668"}
ENISA EUVD ↗
16 Sep 2024, 22:41 UTC
Vendor guidanceAuthoritative vendor guidance changed: added patch: portal.msrc.microsoft.com/CVE-2017-11770; added remediation: portal.msrc.microsoft.com/CVE-2017-11770; removed vendor advisory: access.redhat.com/RHSA-2017:3248.
Before
vendor advisory: access.redhat.com/RHSA-2017:3248
After
patch: portal.msrc.microsoft.com/CVE-2017-11770 · remediation: portal.msrc.microsoft.com/CVE-2017-11770
portal.msrc.microsoft.com ↗
16 Sep 2024, 22:41 UTC
Affected versionsThe structured affected or fixed version information changed.
Before
.NET Core 1.0, .NET Core 1.1, and .NET Core 2.0 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
After
.NET Core 1.0, .NET Core 1.1, and .NET Core 2.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
CNA ↗
16 Sep 2024, 22:41 UTC
Remediation statusRemediation status changed from Awaiting fix to Patch available.
Before
Awaiting fix
After
Patch available
portal.msrc.microsoft.com ↗
16 Sep 2024, 22:41 UTC
SeveritySeverity changed from Unknown to High.
Before
Unknown
After
High
NIST NVD ↗
16 Sep 2024, 22:41 UTC
CVSS scoreCVSS score changed from not recorded to 7.5 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Before
not recorded
After
7.5 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
NIST NVD ↗
16 Sep 2024, 22:41 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2017-11-15CVE published

2024-09-16Fixed release or patch reference recorded

ENISA EUVD · EUVD-2022-1668↗Patch or update reference↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

.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

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2022-1668

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication