GHSA-qj4x-9g63-25g6
XWiki Platform Old Core: Resource path traversal via /skin/ action endpoint in Jetty 12+
Details
### Impact
With Jetty 12+ a user can craft a URL to access any resource the Jetty instance is allowed to access.
For example `http://[host]/xwiki/bin/skin/..%252f/..%252f..%252f..%252f..%252f..%252f..%252f..%252fetc/passwd` allows downloading the content of the /etc/passwd file, provided Jetty is allowed to read it, and if your XWiki webapp is located exactly 5 levels below `/` (like `/var/lib/jetty/webapps/xwiki`, which is the case in the docker image, for example).
Another example which does not go out of the XWiki webapp, but it's still a vulnerability (since users should not be allowed to access Hibernate or XWiki configuration files) is `http://[host]/xwiki/bin/skin/..%252f/..%252fWEB-INF/xwiki.cfg`.
### Patches
This vulnerability has been patched in XWiki 17.10.5 and 18.2.0.
### Workarounds
A possible workaround is to use a different application server, like Jetty < 12 (in the case of XWiki < 17) or Tomcat, which don't seem to be impacted.
### Resources
* https://jira.xwiki.org/browse/XWIKI-24075 * https://jira.xwiki.org/browse/XCOMMONS-3594
### For more information
If there are any questions or comments about this advisory: * Open an issue in [Jira XWiki.org](https://jira.xwiki.org/) * Send an email to the [Security Mailing List](mailto:security@xwiki.org)
### Attribution
Lê Ngọc Khoa reported the vulnerability.
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Affected packages
0 Fixed in: 17.10.5 # pom.xml: bump <version>17.10.5</version> for org.xwiki.platform:xwiki-platform-oldcore 18.0.0-rc-1 Fixed in: 18.2.0 # pom.xml: bump <version>18.2.0</version> for org.xwiki.platform:xwiki-platform-oldcore