CVE-2021-41411: Drools core XML External Entity Reference Vulnerability

CRITICAL
Advisory Identifier: GHSA-rc57-9r3x-98cq
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CVSS 9.8
CWE-611
Published
Advisory Summary

CVE-2021-41411 is a CRITICAL (CVSS 9.8) xml external entity reference vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Drools core libraries in the Maven ecosystem. The issue involves xml external entity reference in drools. Remediation is available by upgrading affected packages to version 7.60.0.Final.

CVE-2021-41411 at a Glance

CVE Identifier CVE-2021-41411
GHSA Identifier GHSA-rc57-9r3x-98cq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Drools core
Package Ecosystem Maven
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-2021-41411

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

org.drools:drools-core fixed: 7.60.0.Final 
<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-core</artifactId>
    <version>7.60.0.Final</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.drools

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-41411, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.drools

Analyze the terminal output to locate any version of Drools core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.60.0.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.drools command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

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 Drools core, 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

drools <=7.59.x is affected by an XML External Entity (XXE) vulnerability in KieModuleMarshaller.java. The Validator class is not used correctly, resulting in the XXE injection vulnerability.

CVE-2021-41411 Affected Drools core Versions

1 component(s)
Fixed Versions:
7.60.0.Final
Product / Package Ecosystem Affected Versions Fixed Version
org.drools:drools-core
maven/org.drools/drools-core
Maven
< 7.60.0.Final
7.60.0.Final

References

NVD — CVE-2021-41411 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-41411
Drools core Source Repository REPOSITORY
https://github.com/apache/incubator-kie-drools/pull/3808
Drools core Source Repository REPOSITORY
https://github.com/kiegroup/drools

Frequently Asked Questions

What is CVE-2021-41411?
CVE-2021-41411 is a security vulnerability in Drools core involving XML External Entity Reference in drools under CWE-611: Improper Restriction of XML External Entity Reference.
Which Drools core versions are affected?
Affected versions include releases prior to 7.60.0.Final across affected packages: org.drools:drools-core.
What version fixes CVE-2021-41411?
Upgrading to 7.60.0.Final (or the latest patched release for your respective branch) resolves the vulnerability.
Is drools-core affected?
Yes, org.drools:drools-core is affected in releases prior to 7.60.0.Final. Upgrade your dependency to 7.60.0.Final or later.
What is the CVSS score of CVE-2021-41411?
CVE-2021-41411 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-2021-41411?
CVE-2021-41411 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 Maven dependencies for CVE-2021-41411?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.drools'. 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-rc57-9r3x-98cq",
  "modified" : "2024-07-05T14:26:30Z",
  "published" : "2022-06-17T00:01:28Z",
  "aliases" : [ "CVE-2021-41411" ],
  "summary" : "XML External Entity Reference in drools",
  "details" : "drools <=7.59.x is affected by an XML External Entity (XXE) vulnerability in KieModuleMarshaller.java. The Validator class is not used correctly, resulting in the XXE injection vulnerability.",
  "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" : "Maven",
      "name" : "org.drools:drools-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.60.0.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.59.0.Final"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41411"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/incubator-kie-drools/pull/3808"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kiegroup/drools"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-17T21:54:41Z",
    "nvd_published_at" : "2022-06-16T10:15:00Z"
  }
}