CVE-2021-37626: Contao/core bundle PHP File Inclusion Vulnerability

MODERATE
Advisory Identifier: GHSA-r6mv-ppjc-4hgr
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CVSS 6.7
CWE-94
Published
Advisory Summary

CVE-2021-37626 is a MODERATE (CVSS 6.7) php file inclusion vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Contao/core bundle libraries in the Packagist ecosystem. The issue involves php file inclusion via insert tags. Remediation is available by upgrading affected packages to version 4.4.56, 4.9.18, 4.11.7.

CVE-2021-37626 at a Glance

CVE Identifier CVE-2021-37626
GHSA Identifier GHSA-r6mv-ppjc-4hgr
Severity MODERATE
CVSS v3.1 Base Score 6.7
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Contao/core bundle
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.7

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

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

How to Fix CVE-2021-37626

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

contao/core-bundle fixed: 4.4.56 
Upgrade contao/core-bundle to 4.4.56
contao/core-bundle fixed: 4.9.18 
Upgrade contao/core-bundle to 4.9.18
contao/core-bundle fixed: 4.11.7 
Upgrade contao/core-bundle to 4.11.7
contao/contao fixed: 4.4.56 
Upgrade contao/contao to 4.4.56
contao/contao fixed: 4.9.18 
Upgrade contao/contao to 4.9.18
contao/contao fixed: 4.11.7 
Upgrade contao/contao to 4.11.7
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 contao/core-bundle

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-37626, inspect your project dependencies for Contao/core bundle:

inspect dependencies for contao/core-bundle

Analyze the terminal output to locate any version of Contao/core bundle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.56), 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 Contao/core bundle, 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

### Impact It is possible for untrusted users to load arbitrary PHP files via insert tags. Installations are only affected if there are untrusted back end users. ### Patches Update to Contao 4.4.56, 4.9.18 or 4.11.7. ### Workarounds Disable the login for untrusted back end users. ### References https://contao.org/en/security-advisories/php-file-inclusion-via-insert-tags ### For more information If you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose).

CVE-2021-37626 Affected Contao/core bundle Versions

6 component(s)
Fixed Versions:
4.4.564.9.184.11.7
Product / Package Ecosystem Affected Versions Fixed Version
contao/core-bundle
 Packagist
≥ 4.0.0
< 4.4.56
4.4.56
contao/core-bundle
 Packagist
≥ 4.5.0
< 4.9.18
4.9.18
contao/core-bundle
 Packagist
≥ 4.10.0
< 4.11.7
4.11.7
contao/contao
 Packagist
≥ 4.0.0
< 4.4.56
4.4.56
contao/contao
 Packagist
≥ 4.5.0
< 4.9.18
4.9.18
contao/contao
 Packagist
≥ 4.10.0
< 4.11.7
4.11.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/contao/contao/security/advisories/GHSA-r6mv-ppjc-4hgr
NVD — CVE-2021-37626 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-37626
Contao/core bundle Security Information SECURITY
https://contao.org/en/security-advisories/php-file-inclusion-via-insert-tags.html
Contao/core bundle Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-37626.yaml
Contao/core bundle Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-37626.yaml
Contao/core bundle Source Repository REPOSITORY
https://github.com/contao/contao

Frequently Asked Questions

What is CVE-2021-37626?
CVE-2021-37626 is a security vulnerability in Contao/core bundle involving PHP file inclusion via insert tags under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Contao/core bundle versions are affected?
Affected versions include releases prior to 4.4.56, 4.9.18, 4.11.7 across affected packages: contao/core-bundle, contao/contao.
What version fixes CVE-2021-37626?
Upgrading to 4.4.56, 4.9.18, 4.11.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is contao/core-bundle affected?
Yes, contao/core-bundle is affected in releases prior to 4.4.56, 4.9.18, 4.11.7. Upgrade your dependency to 4.4.56, 4.9.18, 4.11.7 or later.
Is contao/contao affected?
Yes, contao/contao is affected in releases prior to 4.4.56, 4.9.18, 4.11.7. Upgrade your dependency to 4.4.56, 4.9.18, 4.11.7 or later.
What is the CVSS score of CVE-2021-37626?
CVE-2021-37626 has a CVSS v3.1 base score of 6.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L.
What CWE is associated with CVE-2021-37626?
CVE-2021-37626 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-2021-37626?
Run the dependency tree command: 'inspect dependencies for contao/core-bundle'. 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-r6mv-ppjc-4hgr",
  "modified" : "2024-04-22T18:42:22Z",
  "published" : "2021-08-23T19:41:04Z",
  "aliases" : [ "CVE-2021-37626" ],
  "summary" : "PHP file inclusion via insert tags",
  "details" : "### Impact\n\nIt is possible for untrusted users to load arbitrary PHP files via insert tags.\n\nInstallations are only affected if there are untrusted back end users.\n\n### Patches\n\nUpdate to Contao 4.4.56, 4.9.18 or 4.11.7.\n\n### Workarounds\n\nDisable the login for untrusted back end users.\n\n### References\n\nhttps://contao.org/en/security-advisories/php-file-inclusion-via-insert-tags\n\n### For more information\n\nIf you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.4.56"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.5.0"
      }, {
        "fixed" : "4.9.18"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.10.0"
      }, {
        "fixed" : "4.11.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/contao"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.4.56"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/contao"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.5.0"
      }, {
        "fixed" : "4.9.18"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/contao"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.10.0"
      }, {
        "fixed" : "4.11.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/contao/contao/security/advisories/GHSA-r6mv-ppjc-4hgr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-37626"
  }, {
    "type" : "WEB",
    "url" : "https://contao.org/en/security-advisories/php-file-inclusion-via-insert-tags.html"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-37626.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-37626.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/contao/contao"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-23T16:51:34Z",
    "nvd_published_at" : "2021-08-11T23:15:00Z"
  }
}