org.xwiki.commons:xwiki-commons-xml is an XML library used by the open-source wiki platform XWiki. The HTML sanitizer, introduced in version 14.6-rc-1, allows the injection of arbitrary HTML code and thus cross-site scripting via invalid data attributes. This vulnerability does not affect restricted cleaning in HTMLCleaner as there attributes are cleaned and thus characters like / and > are removed in all attribute names. This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by making sure that data attributes only contain allowed characters. There are no known workarounds apart from upgrading to a version including the fix.
Weakness
The product does not neutralize or incorrectly neutralizes invalid characters or byte sequences in the middle of tag names, URI schemes, and other identifiers.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Xwiki |
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