Impact XWiki is vulnerable to a remote code execution (RCE) attack through its user registration feature. This issue allows an attacker to execute arbitrary code by crafting malicious payloads in the "first name" or "last name" fields during user registration. This impacts all installations that have user registration enabled for guests.
To reproduce, register with any username and password and the following payload as "first name": ]]{{/html}}{{async}}{{groovy}}services.logging.getLogger("attacker").error("Attack succeeded){{/groovy}}{{/async}}. In the following page that confirms the success of the registration, the full first name should be displayed, linking to the created user. If the formatting is broken and a log message with content "ERROR attacker - Attack succeeded!" is logged, the attack succeeded.
Patches This vulnerability has been patched in XWiki 14.10.17, 15.5.3 and 15.8 RC1.
Workarounds
In the administration of your wiki, under "Users & Rights" > "Registration" set the "Registration Successful Message" to the following code:
velocity #set($message = $services.localization.render('core.register.successful', 'xwiki/2.1', ['USERLINK', $userName])) #set($userLink = $xwiki.getUserName("$userSpace$userName")) {{info}}$message.replace('USERLINK', "{{html clean=false}}$userLink{{/html}}"){{/info}}
References https://jira.xwiki.org/browse/XWIKI-21173 https://github.com/xwiki/xwiki-platform/commit/b290bfd573c6f7db6cc15a88dd4111d9fcad0d31
Impact
The rollback action is missing a right protection: it means that a user can rollback to a previous version of the page to gain rights they don't have anymore. This vulnerability impacts all version of XWiki since rollback action is available.
Patches
The problem has been patched in XWiki 14.10.16, 15.5.3 and 15.8-rc-1 by ensuring that the rights are checked before performing the rollback.
Workarounds
There's no workaround for this vulnerability, except paying attention to delete old versions of documents that could allow users to gain more rights.
References
JIRA ticket: https://jira.xwiki.org/browse/XWIKI-21257 Commit: 4de72875ca49602796165412741033bfdbf1e680
For more information
If you have any questions or comments about this advisory: Open an issue in Jira XWiki.org Email us at Security Mailing List
Impact
A user able to attach a file to a page can post a malformed TAR file by manipulating file modification times headers, which when parsed by Tika, could cause a denial of service issue via CPU consumption.
Patches This vulnerability has been patched in XWiki 14.10.18, 15.5.3 and 15.8 RC1.
Workarounds
The workaround is to download commons-compress 1.24 and replace the one located in XWiki WEB-INF/lib/ folder.
References
https://jira.xwiki.org/browse/XCOMMONS-2796
For more information
If you have any questions or comments about this advisory: Open an issue in Jira XWiki.org Email us at Security Mailing List