libgdx/libgdx

Security Vulnerability - Action Required: XXE vulnerability in the newest version of the libgdx

Crispy-fried-chicken opened this issue · 1 comments

Crispy-fried-chicken commented

I think your project may be vulnerable to Improper Restriction of XML External Entity Reference. It shares similarities to a recent CVE disclosure CVE-2021-3878 in the stanfordnlp/CoreNLP. The vulnerable methods are as follows:

  1. com.badlogic.gdx.setup.ExternalExtensionsDialog.initData() in the file extensions/gdx-setup/src/com/badlogic/gdx/setup/ExternalExtensionsDialog.java

The source vulnerability information is as follows:

Vulnerability Detail:
CVE Identifier: CVE-2021-3878
Description: corenlp is vulnerable to Improper Restriction of XML External Entity Reference
Reference:https://nvd.nist.gov/vuln/detail/CVE-2021-3878.
Patch: stanfordnlp/CoreNLP@e5bbe13.

Vulnerability Description:
This vulnerability occurs because of the Improper Restriction of XML External Entity Reference. Given that the XML schema files which is compromised by a hacker, the victim conducts regular process may result in an XML External Entity (XXE) Injection attack. In this file, /com/badlogic/gdx/setup/data/extensions.xml will be parsed, if this file has been tempered with, the user's system wiil be attacked and in an unsafe state.

Recommended Actions:
The corresponding fixes are similar to CVE-2021-3878 to some extent. I have provided the following fixes by applying several patching statements, ensuring that the external entities and DTDs are not loaded when parsing and processing XML documents using the document builder. You can call the function safeDocumentBuilderFactory I defined below instead of directly calling DocumentBuilderFactory.newInstance() to create a DocumentBuilderFactory object to avoid XXE attacks.

  public static DocumentBuilderFactory safeDocumentBuilderFactory() {
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    try {
      dbf.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
      dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
      dbf.setFeature("http://xml.org/sax/features/external-general-entities", false);
      dbf.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
      dbf.setFeature("http://apache.org/xml/features/dom/create-entity-ref-nodes", false);
      dbf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
    } catch (ParserConfigurationException e) {
      log.warn(e);
    }
    return dbf;
  }

Considering the potential riskes it may have, I am willing to cooperate with your to verify, address, and report the identified vulnerability promptly through responsible means. If you require any further information or assistance, please do not hesitate to reach out to me.
Thank you and looking forward to hearing from you soon.

PokeMMO commented

This is an internal file, if someone can edit this they can edit code directly.

Low effort automated scans without manual verification before posting should be discouraged.

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