CVE Vulnerabilities

CVE-2023-37908

Improper Neutralization of Script in Attributes in a Web Page

Published: Oct 25, 2023 | Modified: Nov 21, 2024
CVSS 3.x
9.6
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

XWiki Rendering is a generic Rendering system that converts textual input in a given syntax into another syntax. The cleaning of attributes during XHTML rendering, introduced in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid attribute names. This can be exploited, e.g., via the link syntax in any content that supports XWiki syntax like comments in XWiki. When a user moves the mouse over a malicious link, the malicious JavaScript code is executed in the context of the user session. When this user is a privileged user who has programming rights, this allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance. While this attribute was correctly recognized as not allowed, the attribute was still printed with a prefix data-xwiki-translated-attribute- without further cleaning or validation. This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by removing characters not allowed in data attributes and then validating the cleaned attribute again. There are no known workarounds apart from upgrading to a version including the fix.

Weakness

The product does not neutralize or incorrectly neutralizes “javascript:” or other URIs from dangerous attributes within tags, such as onmouseover, onload, onerror, or style.

Affected Software

Name Vendor Start Version End Version
Xwiki-rendering Xwiki 14.6 (including) 14.10.4 (excluding)

Potential Mitigations

  • Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
  • The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.

References