CVE-2021-41749: Nystudio107/craft seomatic Code Injection Vulnerability

CRITICAL
Advisory Identifier: GHSA-g7xr-v82w-qggq
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CVSS 9.8
CWE-94
Published
Advisory Summary

CVE-2021-41749 is a CRITICAL (CVSS 9.8) code injection vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Nystudio107/craft seomatic libraries in the Packagist ecosystem. The issue involves code injection in seomatic. Remediation is available by upgrading affected packages to version 3.4.11.

CVE-2021-41749 at a Glance

CVE Identifier CVE-2021-41749
GHSA Identifier GHSA-g7xr-v82w-qggq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Nystudio107/craft seomatic
Package Ecosystem Packagist
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-2021-41749

To remediate this vulnerability, upgrade all affected Nystudio107/craft seomatic dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nystudio107/craft-seomatic fixed: 3.4.11 
Upgrade nystudio107/craft-seomatic to 3.4.11
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 nystudio107/craft-seomatic

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-41749, inspect your project dependencies for Nystudio107/craft seomatic:

inspect dependencies for nystudio107/craft-seomatic

Analyze the terminal output to locate any version of Nystudio107/craft seomatic in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.4.11), 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-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Nystudio107/craft seomatic, 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

In the SEOmatic plugin up to 3.4.11 for Craft CMS 3, it is possible for unauthenticated attackers to perform a Server-Side Template Injection, allowing for remote code execution.

CVE-2021-41749 Affected Nystudio107/craft seomatic Versions

1 component(s)
Fixed Versions:
3.4.11
Product / Package Ecosystem Affected Versions Fixed Version
nystudio107/craft-seomatic
 Packagist
< 3.4.11
3.4.11

References

NVD — CVE-2021-41749 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-41749
Security Fix Commit FIX COMMIT
https://github.com/nystudio107/craft-seomatic/commit/3fee7d50147cdf3f999cfc1e04cbc3fb3d9f2f7d
Nystudio107/craft seomatic Source Repository REPOSITORY
https://github.com/nystudio107/craft-seomatic
Nystudio107/craft seomatic Source Repository REPOSITORY
https://github.com/nystudio107/craft-seomatic/blob/develop/CHANGELOG.md

Frequently Asked Questions

What is CVE-2021-41749?
CVE-2021-41749 is a security vulnerability in Nystudio107/craft seomatic involving Code Injection in SEOmatic under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Nystudio107/craft seomatic versions are affected?
Affected versions include releases prior to 3.4.11 across affected packages: nystudio107/craft-seomatic.
What version fixes CVE-2021-41749?
Upgrading to 3.4.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nystudio107/craft-seomatic affected?
Yes, nystudio107/craft-seomatic is affected in releases prior to 3.4.11. Upgrade your dependency to 3.4.11 or later.
What is the CVSS score of CVE-2021-41749?
CVE-2021-41749 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-2021-41749?
CVE-2021-41749 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check Packagist dependencies for CVE-2021-41749?
Run the dependency tree command: 'inspect dependencies for nystudio107/craft-seomatic'. 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-g7xr-v82w-qggq",
  "modified" : "2022-06-20T22:35:33Z",
  "published" : "2022-06-13T00:00:19Z",
  "aliases" : [ "CVE-2021-41749" ],
  "summary" : "Code Injection in SEOmatic",
  "details" : "In the SEOmatic plugin up to 3.4.11 for Craft CMS 3, it is possible for unauthenticated attackers to perform a Server-Side Template Injection, allowing for remote code execution.",
  "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" : "Packagist",
      "name" : "nystudio107/craft-seomatic"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.4.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41749"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nystudio107/craft-seomatic/commit/3fee7d50147cdf3f999cfc1e04cbc3fb3d9f2f7d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nystudio107/craft-seomatic"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nystudio107/craft-seomatic/blob/develop/CHANGELOG.md"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-20T22:35:33Z",
    "nvd_published_at" : "2022-06-12T11:15:00Z"
  }
}