CVE-2021-4248: DNS DNS NuGet Package Uses Insufficiently Vulnerability

CRITICAL
Advisory Identifier: GHSA-g3wc-xv93-445q
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CVSS 9.8
CWE-330
Published
Advisory Summary

CVE-2021-4248 is a CRITICAL (CVSS 9.8) dns nuget package uses insufficiently vulnerability (CWE-330: Use of Insufficiently Random Values) affecting DNS libraries in the NuGet ecosystem. The issue involves dns nuget package uses insufficiently random values. Remediation is available by upgrading affected packages to version 7.0.0.

CVE-2021-4248 at a Glance

CVE Identifier CVE-2021-4248
GHSA Identifier GHSA-g3wc-xv93-445q
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-330: Use of Insufficiently Random Values
Affected Product DNS
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-4248

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

DNS fixed: 7.0.0 
Upgrade DNS to 7.0.0
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 DNS

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-4248, inspect your project dependencies for DNS:

inspect dependencies for DNS

Analyze the terminal output to locate any version of DNS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.0.0), 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-330: Use of Insufficiently Random Values, where the product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. In DNS, 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 vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The attack may be launched remotely. Upgrading to version 7.0.0 can address this issue. The name of the patch is cf7105aa2aae90d6656088fe5a8ee1d5730773b6. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-216188.

CVE-2021-4248 Affected DNS Versions

1 component(s)
Fixed Versions:
7.0.0
Product / Package Ecosystem Affected Versions Fixed Version
DNS
nuget/DNS
NuGet
< 7.0.0
7.0.0

References

NVD — CVE-2021-4248 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-4248
DNS Source Repository REPOSITORY
https://github.com/kapetan/dns/pull/88
Security Fix Commit FIX COMMIT
https://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6
DNS Source Repository REPOSITORY
https://github.com/kapetan/dns
DNS Release RELEASE
https://github.com/kapetan/dns/releases/tag/v7.0.0
vuldb.com/ WEB
https://vuldb.com/?id.216188

Frequently Asked Questions

What is CVE-2021-4248?
CVE-2021-4248 is a security vulnerability in DNS involving DNS NuGet package uses insufficiently random values under CWE-330: Use of Insufficiently Random Values.
Which DNS versions are affected?
Affected versions include releases prior to 7.0.0 across affected packages: DNS.
What version fixes CVE-2021-4248?
Upgrading to 7.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is DNS affected?
Yes, DNS is affected in releases prior to 7.0.0. Upgrade your dependency to 7.0.0 or later.
What is the CVSS score of CVE-2021-4248?
CVE-2021-4248 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-4248?
CVE-2021-4248 is classified under CWE-330: Use of Insufficiently Random Values (The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.).
How can I check NuGet dependencies for CVE-2021-4248?
Run the dependency tree command: 'inspect dependencies for DNS'. 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-g3wc-xv93-445q",
  "modified" : "2022-12-22T23:06:24Z",
  "published" : "2022-12-18T12:30:20Z",
  "aliases" : [ "CVE-2021-4248" ],
  "summary" : "DNS NuGet package uses insufficiently random values",
  "details" : "A vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The attack may be launched remotely. Upgrading to version 7.0.0 can address this issue. The name of the patch is cf7105aa2aae90d6656088fe5a8ee1d5730773b6. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-216188.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "DNS"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-4248"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kapetan/dns/pull/88"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kapetan/dns"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kapetan/dns/releases/tag/v7.0.0"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/?id.216188"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-330" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-12-22T23:06:24Z",
    "nvd_published_at" : "2022-12-18T11:15:00Z"
  }
}