CVE-2019-18213 : Security Advisory and Response

The XML Language Server (lsp4xml), versions prior to 0.9.1, utilized in Red Hat XML Language Support for Visual Studio, is vulnerable to XXE attacks leading to SSRF and potential SMB connection initiation.

Understanding CVE-2019-18213

This CVE involves a security vulnerability in the XML Language Server (lsp4xml) that can be exploited through specially crafted XML documents.

What is CVE-2019-18213?

The vulnerability in lsp4xml versions before 0.9.1 allows for XXE attacks, potentially enabling SSRF and SMB connection initiation, which can lead to NetNTLM challenge/response capture for password cracking.

The Impact of CVE-2019-18213

Exploiting this vulnerability can result in server-side request forgery (SSRF) and the initiation of SMB connections, posing a risk of sensitive data exposure and potential password cracking.

Technical Details of CVE-2019-18213

The technical aspects of this CVE include:

Vulnerability Description

The vulnerability exists in the LSPXMLParserConfiguration.java file within the extensions/contentmodel/participants/diagnostics directory of lsp4xml versions prior to 0.9.1.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: All versions prior to 0.9.1

Exploitation Mechanism

The vulnerability can be exploited through a specially crafted XML document, allowing attackers to perform XXE attacks and potentially initiate SSRF and SMB connections.

Mitigation and Prevention

To address CVE-2019-18213, consider the following mitigation strategies:

Immediate Steps to Take

Update lsp4xml to version 0.9.1 or later to mitigate the vulnerability.
Avoid processing untrusted XML documents to prevent XXE attacks.

Long-Term Security Practices

Regularly monitor and update software dependencies to address known vulnerabilities.
Implement network segmentation to restrict SMB connections and reduce the attack surface.

Patching and Updates

Stay informed about security advisories and patches related to lsp4xml.
Apply security patches promptly to protect against potential exploits.