CVE-2018-0765: System.Security.Cryptography.Xml Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-35hc-x2cw-2j4v
Share
CVSS 7.5
CWE-611
Published
Advisory Summary

CVE-2018-0765 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting System.Security.Cryptography.Xml libraries in the NuGet ecosystem. The issue involves denial of service vulnerability exists when .net and .net core improperly process xml documents. Remediation is available by upgrading affected packages to version 4.4.2.

CVE-2018-0765 at a Glance

CVE Identifier CVE-2018-0765
GHSA Identifier GHSA-35hc-x2cw-2j4v
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product System.Security.Cryptography.Xml
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-2018-0765

To remediate this vulnerability, upgrade all affected System.Security.Cryptography.Xml 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.Xml fixed: 4.4.2 
Upgrade System.Security.Cryptography.Xml to 4.4.2
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.Xml

How to Check if You Are Affected

To determine whether your application is affected by CVE-2018-0765, inspect your project dependencies for System.Security.Cryptography.Xml:

inspect dependencies for System.Security.Cryptography.Xml

Analyze the terminal output to locate any version of System.Security.Cryptography.Xml in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.2), 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-611: Improper Restriction of XML External Entity Reference, where the product processes an xml document that can contain xml entities with uris that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. In System.Security.Cryptography.Xml, 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

A denial of service vulnerability exists when .NET and .NET Core improperly process XML documents, aka ".NET and .NET Core Denial of Service Vulnerability." This affects Microsoft .NET Framework 2.0, Microsoft .NET Framework 3.0, Microsoft .NET Framework 4.7.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1, Microsoft .NET Framework 4.5.2, Microsoft .NET Framework 4.7/4.7.1, Microsoft .NET Framework 4.6, Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2, Microsoft .NET Framework 4.6.2/4.7/4.7.1, .NET Core 2.0, Microsoft .NET Framework 4.7.2.

CVE-2018-0765 Affected System.Security.Cryptography.Xml Versions

1 component(s)
Fixed Versions:
4.4.2
Product / Package Ecosystem Affected Versions Fixed Version
System.Security.Cryptography.Xml
nuget/System.Security.Cryptography.Xml
NuGet
< 4.4.2
4.4.2

References

NVD — CVE-2018-0765 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-0765
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-35hc-x2cw-2j4v
System.Security.Cryptography.Xml Security Information SECURITY
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0765
System.Security.Cryptography.Xml Security Information SECURITY
http://www.securityfocus.com/bid/104060
System.Security.Cryptography.Xml Security Information SECURITY
http://www.securitytracker.com/id/1040851

Frequently Asked Questions

What is CVE-2018-0765?
CVE-2018-0765 is a security vulnerability in System.Security.Cryptography.Xml involving Denial of service vulnerability exists when .NET and .NET Core improperly process XML documents under CWE-611: Improper Restriction of XML External Entity Reference.
Which System.Security.Cryptography.Xml versions are affected?
Affected versions include releases prior to 4.4.2 across affected packages: System.Security.Cryptography.Xml.
What version fixes CVE-2018-0765?
Upgrading to 4.4.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is System.Security.Cryptography.Xml affected?
Yes, System.Security.Cryptography.Xml is affected in releases prior to 4.4.2. Upgrade your dependency to 4.4.2 or later.
What is the CVSS score of CVE-2018-0765?
CVE-2018-0765 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-2018-0765?
CVE-2018-0765 is classified under CWE-611: Improper Restriction of XML External Entity Reference (The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.).
How can I check NuGet dependencies for CVE-2018-0765?
Run the dependency tree command: 'inspect dependencies for System.Security.Cryptography.Xml'. 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-35hc-x2cw-2j4v",
  "modified" : "2022-04-26T19:04:54Z",
  "published" : "2018-10-16T19:54:06Z",
  "aliases" : [ "CVE-2018-0765" ],
  "summary" : "Denial of service vulnerability exists when .NET and .NET Core improperly process XML documents",
  "details" : "A denial of service vulnerability exists when .NET and .NET Core improperly process XML documents, aka \".NET and .NET Core Denial of Service Vulnerability.\" This affects Microsoft .NET Framework 2.0, Microsoft .NET Framework 3.0, Microsoft .NET Framework 4.7.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1, Microsoft .NET Framework 4.5.2, Microsoft .NET Framework 4.7/4.7.1, Microsoft .NET Framework 4.6, Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2, Microsoft .NET Framework 4.6.2/4.7/4.7.1, .NET Core 2.0, Microsoft .NET Framework 4.7.2.",
  "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.Xml"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.4.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-0765"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-35hc-x2cw-2j4v"
  }, {
    "type" : "WEB",
    "url" : "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0765"
  }, {
    "type" : "WEB",
    "url" : "http://www.securityfocus.com/bid/104060"
  }, {
    "type" : "WEB",
    "url" : "http://www.securitytracker.com/id/1040851"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T20:54:06Z",
    "nvd_published_at" : null
  }
}