XWiki Platform Flamingo Theme UI is a tool that allows customization and preview of any Flamingo-based skin. Starting with versions 6.2.4 and 6.3-rc-1, a possible cross-site scripting vector is present in the FlamingoThemesCode.WebHomeSheet wiki page related to the newThemeName form field. The issue is patched in versions 12.10.11, 14.0-rc-1, 13.4.7, and 13.10.3. The easiest available workaround is to edit the wiki page FlamingoThemesCode.WebHomeSheet (with wiki editor) according to the suggestion provided in the GitHub Security Advisory.
Weakness
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as “<”, “>”, and “&” that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Xwiki |
Xwiki |
6.2.4 (including) |
12.10.11 (excluding) |
| Xwiki |
Xwiki |
13.0 (including) |
13.4.7 (excluding) |
| Xwiki |
Xwiki |
13.5 (including) |
13.10.3 (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