GHSA-x37v-36wv-6v6h Cross-site Scripting in org.xwiki.commons:xwiki-commons-xml

• Maven org.xwiki.commons:xwiki-commons-xml: >= 4.2-milestone-1, < 14.10 → fixed in 14.10

Impact The "restricted" mode of the HTML cleaner in XWiki, introduced in version 4.2-milestone-1 and massively improved in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid HTML comments. As a consequence, any code relying on this "restricted" mode for security is vulnerable to JavaScript injection ("cross-site scripting"/XSS). An example are anonymous comments in XWiki where the HTML macro filters HTML using restricted mode: ```html {{html}} {{/html}} ``` When a privileged user with programming rights visits such a comment in XWiki, the malicious JavaScript code is executed in the context of the user session. This allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance. Note that while all versions since 4.2-milestone-1 should be vulnerable, only starting with version 14.6-rc-1 the HTML comment is necessary for the attack to succeed due to another vulnerability that has been patched in version 14.6-rc-1. Patches This problem has been patched in XWiki 14.10, HTML comments are now removed in restricted mode and a check has been introduced that ensures that comments don't start with `>`. Workarounds There are no known workarounds apart from upgrading to a version including the fix. References • https://jira.xwiki.org/browse/XCOMMONS-2568 • https://jira.xwiki.org/browse/XWIKI-20348 • https://github.com/xwiki/xwiki-commons/commit/8ff1a9d7e5d7b45b690134a537d53dc05cae04ab For more information If you have any questions or comments about this advisory: • Open an issue in Jira XWiki • Email us at XWiki Security mailing-list Attribution This vulnerability was reported on Intigriti by ynoof @Ynoof5.