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Full vulnerability report · 2020
CVE-2020-1108High confidence

.NET Core & .NET Framework Denial of Service Vulnerability

Microsoft · .NET 5.0

7.5HighCVSS 3.1
Recommended action
Within 7 days

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

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2020-1108 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitydotnet: Denial of service via untrusted input
196 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • rh-dotnet21-0:2.1-17.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-0:2.1-17.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-0:2.1-18.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-0:2.1-18.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-0:2.1.514-2.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-0:2.1.515-1.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-debuginfo-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-debuginfo-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-host-0:2.1.18-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
  • rh-dotnet21-dotnet-host-0:2.1.19-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7)
Summary
An integer overflow condition was found in dotnet and dotnet3.1's BinaryReader Read7BitEncodedInt() method. This method is used by BinaryReader's ReadString() method, and given a certain input, and cause a denial of service to dotnet applications using BinaryReader. The exploitation of this flaw depends on the application but does not inherently require the attacker to be authenticated or have any specific privileges. An attacker could exploit this flaw remotely via the internet by sending crafted data to a dotnet application that is passed into Read7BitEncodedInt(), resulting in a denial of service when the output is used by ReadString().
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-2252

No EUVD known-exploited evidence

A denial of service vulnerability exists when .NET Core or .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Core or .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Core or .NET Framework application. The update addresses the vulnerability by correcting how the .NET Core or .NET Framework web application handles web requests.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
0.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

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

Patch available
01

What, why and how

A denial of service vulnerability exists when .NET Core or .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Core or .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Core or .NET Framework application. The update addresses the vulnerability by correcting how the .NET Core or .NET Framework web application handles web requests.

What

A denial of service vulnerability exists when .NET Core or .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Core or .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Core or .NET Framework application. The update addresses the vulnerability by correcting how the .NET Core or .NET Framework web application handles web requests.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

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

A denial of service vulnerability exists when .NET Core or .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Core or .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Core or .NET Framework application. The update addresses the vulnerability by correcting how the .NET Core or .NET Framework web application handles web requests.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

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.

02

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 → vulnerable operation → 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.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: 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 service
A

Official authority intelligence

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

ENISA EUVD · EUVD-2022-2252Official EUVD mapping

A denial of service vulnerability exists when .NET Core or .NET Framework improperly handles web requests. An attacker who successfully exploited this vulnerability could cause a denial of service against a .NET Core or .NET Framework web application. The vulnerability can be exploited remotely, without authentication. A remote unauthenticated attacker could exploit this vulnerability by issuing specially crafted requests to the .NET Core or .NET Framework application. The update addresses the vulnerability by correcting how the .NET Core or .NET Framework web application handles web requests.

Official EUVD record
CERT-FR · French · CERTFR-2020-AVI-289Multiples vulnérabilités dans les produits Microsoft

De multiples vulnérabilités ont été corrigées dans les produits Microsoft . Elles permettent à un attaquant de provoquer un déni de service, une exécution de code à distance et une usurpation d'identité.

Official advisory
CERT-FR · French · CERTFR-2020-AVI-288Multiples vulnérabilités dans Microsoft .Net

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

Official advisory
03

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
5.0.0 < publication; 2.1 < publication; 3.1 < publication; 2.0.0 < publication; 3.0.0 < publication; 3.5.0 < publication; 3.0.0.0 < publication
Fixed
rh-dotnet21-0:2.1-17.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-0:2.1-17.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-0:2.1-18.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-0:2.1-18.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-0:2.1.514-2.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-0:2.1.515-1.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-debuginfo-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-debuginfo-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-host-0:2.1.18-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-host-0:2.1.19-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-runtime-2.1-0:2.1.18-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-runtime-2.1-0:2.1.19-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-sdk-2.1-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-sdk-2.1-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-sdk-2.1.5xx-0:2.1.514-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-dotnet-sdk-2.1.5xx-0:2.1.515-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-runtime-0:2.1-17.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet21-runtime-0:2.1-18.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-aspnetcore-runtime-3.1-0:3.1.4-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-aspnetcore-runtime-3.1-0:3.1.5-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-aspnetcore-targeting-pack-3.1-0:3.1.4-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-aspnetcore-targeting-pack-3.1-0:3.1.5-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-0:3.1.104-2.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-0:3.1.104-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-0:3.1.105-1.el7.src as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-0:3.1.105-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-apphost-pack-3.1-0:3.1.4-2.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); rh-dotnet31-dotnet-apphost-pack-3.1-0:3.1.5-1.el7.x86_64 as a component of .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7); and 166 more
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
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.
04

Evidence and provenance

Published 21 May 2020 · Last source change 19 Aug 2026, 16:34 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2022-2252
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceUnavailable
NVD statusNVD modified after enrichment

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →
  1. Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link · patch to authoritative remediation link · patch.
    Before
    authoritative remediation link · patch
    After
    authoritative remediation link · patch
    af854a3a-2127-422b-91ae-364da2661108 ↗
  2. Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link · patch to authoritative remediation link · patch.
    Before
    authoritative remediation link · patch
    After
    authoritative remediation link · patch
    f38d906d-7342-40ea-92c1-6c4a2c6478c8 ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    3.1; 2.1; unspecified; 16.0; 6.2 · 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.
    After
    5.0.0 < publication; 2.1 < publication; 3.1 < publication; 2.0.0 < publication; 3.0.0 < publication; 3.5.0 < publication; 3.0.0.0 < publication · 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 ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2022-2252↗Vendor CSAF · Red Hat Product Security↗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.
Free version - for non-commercial use only.CVE-2020-1108 · cve.blacktree.nl