CVE-2017-11770: System.Security.Cryptography.X509Certificates Improper Certificate Validation Vulnerability

HIGH
Advisory Identifier: GHSA-7mfr-774f-w5r9
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CVSS 7.5
CWE-295
Published
Advisory Summary

CVE-2017-11770 is a HIGH (CVSS 7.5) improper certificate validation vulnerability (CWE-295: Improper Certificate Validation) affecting System.Security.Cryptography.X509Certificates libraries in the NuGet ecosystem. The issue involves improper certificate validation. Remediation is available by upgrading affected packages to version 4.1.2, 2.0.3.

CVE-2017-11770 at a Glance

CVE Identifier CVE-2017-11770
GHSA Identifier GHSA-7mfr-774f-w5r9
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-295: Improper Certificate Validation
Affected Product System.Security.Cryptography.X509Certificates
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2017-11770

To remediate this vulnerability, upgrade all affected System.Security.Cryptography.X509Certificates dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

System.Security.Cryptography.X509Certificates fixed: 4.1.2 
Upgrade System.Security.Cryptography.X509Certificates to 4.1.2
Microsoft.NETCore.App fixed: 2.0.3 
Upgrade Microsoft.NETCore.App to 2.0.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for System.Security.Cryptography.X509Certificates

How to Check if You Are Affected

To determine whether your application is affected by CVE-2017-11770, inspect your project dependencies for System.Security.Cryptography.X509Certificates:

inspect dependencies for System.Security.Cryptography.X509Certificates

Analyze the terminal output to locate any version of System.Security.Cryptography.X509Certificates in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.1.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-295: Improper Certificate Validation, where the product does not validate, or incorrectly validates, a certificate. In System.Security.Cryptography.X509Certificates, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

.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".

CVE-2017-11770 Affected System.Security.Cryptography.X509Certificates Versions

2 component(s)
Fixed Versions:
4.1.22.0.3
Product / Package Ecosystem Affected Versions Fixed Version
System.Security.Cryptography.X509Certificates
nuget/System.Security.Cryptography.X509Certificates
NuGet
≥ 4.0.0
< 4.1.2
4.1.2
Microsoft.NETCore.App
nuget/Microsoft.NETCore.App
NuGet
≥ 1.0.0
< 2.0.3
2.0.3

References

NVD — CVE-2017-11770 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-11770
access.redhat.com/errata/rhsa-2017:32... WEB
https://access.redhat.com/errata/RHSA-2017:3248
System.Security.Cryptography.X509Certificates Security Information SECURITY
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11770
System.Security.Cryptography.X509Certificates Security Information SECURITY
http://www.securityfocus.com/bid/101710
System.Security.Cryptography.X509Certificates Security Information SECURITY
http://www.securitytracker.com/id/1039787

Frequently Asked Questions

What is CVE-2017-11770?
CVE-2017-11770 is a security vulnerability in System.Security.Cryptography.X509Certificates involving Improper Certificate Validation under CWE-295: Improper Certificate Validation.
Which System.Security.Cryptography.X509Certificates versions are affected?
Affected versions include releases prior to 4.1.2, 2.0.3 across affected packages: System.Security.Cryptography.X509Certificates, Microsoft.NETCore.App.
What version fixes CVE-2017-11770?
Upgrading to 4.1.2, 2.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is System.Security.Cryptography.X509Certificates affected?
Yes, System.Security.Cryptography.X509Certificates is affected in releases prior to 4.1.2. Upgrade your dependency to 4.1.2 or later.
Is Microsoft.NETCore.App affected?
Yes, Microsoft.NETCore.App is affected in releases prior to 2.0.3. Upgrade your dependency to 2.0.3 or later.
What is the CVSS score of CVE-2017-11770?
CVE-2017-11770 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2017-11770?
CVE-2017-11770 is classified under CWE-295: Improper Certificate Validation (The product does not validate, or incorrectly validates, a certificate.).
How can I check NuGet dependencies for CVE-2017-11770?
Run the dependency tree command: 'inspect dependencies for System.Security.Cryptography.X509Certificates'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7mfr-774f-w5r9",
  "modified" : "2022-04-12T00:07:34Z",
  "published" : "2022-04-12T00:07:34Z",
  "aliases" : [ "CVE-2017-11770" ],
  "summary" : "Improper Certificate Validation",
  "details" : ".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\".",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "System.Security.Cryptography.X509Certificates"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.1.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0"
      }, {
        "fixed" : "2.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-11770"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2017:3248"
  }, {
    "type" : "WEB",
    "url" : "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11770"
  }, {
    "type" : "WEB",
    "url" : "http://www.securityfocus.com/bid/101710"
  }, {
    "type" : "WEB",
    "url" : "http://www.securitytracker.com/id/1039787"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-295" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-04-12T00:07:34Z",
    "nvd_published_at" : null
  }
}