Description
XML Language Server (aka lsp4xml) before 0.9.1, as used in Red Hat XML Language Support (aka vscode-xml) before 0.9.1 for Visual Studio and other products, allows XXE via a crafted XML document, with resultant SSRF (as well as SMB connection initiation that can lead to NetNTLM challenge/response capture for password cracking). This occurs in extensions/contentmodel/participants/diagnostics/LSPXMLParserConfiguration.java.
Remediation
References
https://github.com/angelozerr/lsp4xml/
https://github.com/angelozerr/lsp4xml/blob/master/CHANGELOG.md#others
https://github.com/angelozerr/lsp4xml/pull/566
https://github.com/redhat-developer/vscode-xml/
https://marketplace.visualstudio.com/items?itemName=redhat.vscode-xml
https://www.shielder.it/blog/dont-open-that-xml-xxe-to-rce-in-xml-plugins-for-vs-code-eclipse-theia/
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CVE-2021-20218 Vulnerability in maven package io.fabric8:kubernetes-client