CVE-2021-23901: Nutch XML External Entity (XXE) Injection Vulnerability

CRITICAL
Advisory Identifier: GHSA-fxhp-wrw9-3r97
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CVSS 9.1
CWE-611
Published
Advisory Summary

CVE-2021-23901 is a CRITICAL (CVSS 9.1) xml external entity (xxe) injection vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Nutch libraries in the Maven ecosystem. The issue involves xml external entity (xxe) injection in apache nutch. Remediation is available by upgrading affected packages to version 1.18.

CVE-2021-23901 at a Glance

CVE Identifier CVE-2021-23901
GHSA Identifier GHSA-fxhp-wrw9-3r97
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Nutch
Package Ecosystem Maven
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:H/A:N).

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 None (A:N)

How to Fix CVE-2021-23901

To remediate this vulnerability, upgrade all affected Nutch 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.apache.nutch:nutch fixed: 1.18 
<dependency>
    <groupId>org.apache.nutch</groupId>
    <artifactId>nutch</artifactId>
    <version>1.18</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.apache.nutch

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-23901, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.nutch

Analyze the terminal output to locate any version of Nutch in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.nutch 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 Nutch, 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

An XML external entity (XXE) injection vulnerability was discovered in the Nutch DmozParser and is known to affect Nutch versions < 1.18. XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application's processing of XML data. It often allows an attacker to view files on the application server filesystem, and to interact with any back-end or external systems that the application itself can access. This issue is fixed in Apache Nutch 1.18.

CVE-2021-23901 Affected Nutch Versions

1 component(s)
Fixed Versions:
1.18
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.nutch:nutch
maven/org.apache.nutch/nutch
Maven
< 1.18
1.18

References

NVD — CVE-2021-23901 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23901
Nutch Source Repository REPOSITORY
https://github.com/apache/nutch/pull/563
issues.apache.org/jira/browse/nutch-2... WEB
https://issues.apache.org/jira/browse/NUTCH-2841
lists.apache.org/thread.html/r090321... WEB
https://lists.apache.org/thread.html/r090321840b44cc91086c4e317bf2baffa270749dde6c1273b6567f7c%40%3Cdev.nutch.apache.org%3E
lists.apache.org/thread.html/r5e2f77... WEB
https://lists.apache.org/thread.html/r5e2f7737b42c73a3325f3c2c8cdee1ec27631b3a0e144104d84d70e6@%3Cannounce.apache.org%3E
lists.apache.org/thread.html/r7ddfd6... WEB
https://lists.apache.org/thread.html/r7ddfd680aa7ea001ca8da63bb23e3f8caa095a8b4f2261e46bade5c7@%3Cdev.nutch.apache.org%3E
Nutch Security Information SECURITY
https://security.netapp.com/advisory/ntap-20210513-0003

Frequently Asked Questions

What is CVE-2021-23901?
CVE-2021-23901 is a security vulnerability in Nutch involving XML external entity (XXE) injection in Apache Nutch under CWE-611: Improper Restriction of XML External Entity Reference.
Which Nutch versions are affected?
Affected versions include releases prior to 1.18 across affected packages: org.apache.nutch:nutch.
What version fixes CVE-2021-23901?
Upgrading to 1.18 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nutch affected?
Yes, org.apache.nutch:nutch is affected in releases prior to 1.18. Upgrade your dependency to 1.18 or later.
What is the CVSS score of CVE-2021-23901?
CVE-2021-23901 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:H/A:N.
What CWE is associated with CVE-2021-23901?
CVE-2021-23901 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-2021-23901?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.nutch'. 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-fxhp-wrw9-3r97",
  "modified" : "2022-03-18T17:46:29Z",
  "published" : "2022-03-18T17:46:29Z",
  "aliases" : [ "CVE-2021-23901" ],
  "summary" : "XML external entity (XXE) injection in Apache Nutch",
  "details" : "An XML external entity (XXE) injection vulnerability was discovered in the Nutch DmozParser and is known to affect Nutch versions < 1.18. XML external entity injection (also known as XXE) is a web security vulnerability that allows an attacker to interfere with an application's processing of XML data. It often allows an attacker to view files on the application server filesystem, and to interact with any back-end or external systems that the application itself can access.  This issue is fixed in Apache Nutch 1.18.",
  "severity" : [ {
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    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
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    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
        "fixed" : "1.18"
      } ]
    } ]
  } ],
  "references" : [ {
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  }, {
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  }, {
    "type" : "WEB",
    "url" : "https://issues.apache.org/jira/browse/NUTCH-2841"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r090321840b44cc91086c4e317bf2baffa270749dde6c1273b6567f7c%40%3Cdev.nutch.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r5e2f7737b42c73a3325f3c2c8cdee1ec27631b3a0e144104d84d70e6@%3Cannounce.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r7ddfd680aa7ea001ca8da63bb23e3f8caa095a8b4f2261e46bade5c7@%3Cdev.nutch.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20210513-0003"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-06T19:54:36Z",
    "nvd_published_at" : "2021-01-25T10:16:00Z"
  }
}