CVE-2020-25911: Modx/revolution XML External Entity Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-vhfp-9wvj-gwvg
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CVSS 9.1
CWE-611
Published
Advisory Summary

CVE-2020-25911 is a CRITICAL (CVSS 9.1) xml external entity vulnerability vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Modx/revolution libraries in the Packagist ecosystem. The issue involves xml external entity vulnerability in modx cms. Remediation is available by upgrading affected packages to version 2.8.0.

CVE-2020-25911 at a Glance

CVE Identifier CVE-2020-25911
GHSA Identifier GHSA-vhfp-9wvj-gwvg
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Modx/revolution
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 9.1

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: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 High (C:H)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2020-25911

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

modx/revolution fixed: 2.8.0 
Upgrade modx/revolution to 2.8.0
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 modx/revolution

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-25911, inspect your project dependencies for Modx/revolution:

inspect dependencies for modx/revolution

Analyze the terminal output to locate any version of Modx/revolution in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.8.0), 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-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 Modx/revolution, 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 XML External Entity (XXE) vulnerability was discovered in the modRestServiceRequest component in MODX CMS 2.7.3 which can lead to an information disclosure or denial of service (DOS).

CVE-2020-25911 Affected Modx/revolution Versions

1 component(s)
Fixed Versions:
2.8.0
Product / Package Ecosystem Affected Versions Fixed Version
modx/revolution
 Packagist
< 2.8.0
2.8.0

References

NVD — CVE-2020-25911 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-25911
Modx/revolution Source Repository REPOSITORY
https://github.com/modxcms/revolution/issues/15237
Modx/revolution Source Repository REPOSITORY
https://github.com/modxcms/revolution/pull/15238
Modx/revolution Source Repository REPOSITORY
https://github.com/modxcms/revolution/pull/15238/commits/1b7ffe02df30f05dbf67dd15e4d8101687c1585a
Modx/revolution Source Repository REPOSITORY
https://github.com/dahua966/Vul_disclose/blob/main/XXE_modxcms.md
Modx/revolution Source Repository REPOSITORY
https://github.com/modxcms/revolution

Frequently Asked Questions

What is CVE-2020-25911?
CVE-2020-25911 is a security vulnerability in Modx/revolution involving XML External Entity vulnerability in MODX CMS under CWE-611: Improper Restriction of XML External Entity Reference.
Which Modx/revolution versions are affected?
Affected versions include releases prior to 2.8.0 across affected packages: modx/revolution.
What version fixes CVE-2020-25911?
Upgrading to 2.8.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is modx/revolution affected?
Yes, modx/revolution is affected in releases prior to 2.8.0. Upgrade your dependency to 2.8.0 or later.
What is the CVSS score of CVE-2020-25911?
CVE-2020-25911 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
What CWE is associated with CVE-2020-25911?
CVE-2020-25911 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 Packagist dependencies for CVE-2020-25911?
Run the dependency tree command: 'inspect dependencies for modx/revolution'. 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-vhfp-9wvj-gwvg",
  "modified" : "2021-11-03T14:51:31Z",
  "published" : "2021-11-01T19:19:43Z",
  "aliases" : [ "CVE-2020-25911" ],
  "summary" : "XML External Entity vulnerability in MODX CMS",
  "details" : "A XML External Entity (XXE) vulnerability was discovered in the modRestServiceRequest component in MODX CMS 2.7.3 which can lead to an information disclosure or denial of service (DOS).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "modx/revolution"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.8.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-25911"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/modxcms/revolution/issues/15237"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/modxcms/revolution/pull/15238"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/modxcms/revolution/pull/15238/commits/1b7ffe02df30f05dbf67dd15e4d8101687c1585a"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dahua966/Vul_disclose/blob/main/XXE_modxcms.md"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/modxcms/revolution"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-11-01T19:08:06Z",
    "nvd_published_at" : "2021-10-31T19:15:00Z"
  }
}