CVE-2024-34701 in CreateWiki
Summary
by MITRE • 05/14/2024
CreateWiki is Miraheze's MediaWiki extension for requesting & creating wikis. It is possible for users to be considered as the requester of a specific wiki request if their local user ID on any wiki in a wiki farm matches the local ID of the requester at the wiki where the wiki request was made. This allows them to go to that request entry's on Special:RequestWikiQueue on the wiki where their local user ID matches and take any actions that the wiki requester is allowed to take from there.
Commit 02e0f298f8d35155c39aa74193cb7b867432c5b8 fixes the issue. Important note about the fix: This vulnerability has been fixed by disabling access to the REST API and special pages outside of the wiki configured as the "global wiki" in `$wgCreateWikiGlobalWiki` in a user's MediaWiki settings.
As a workaround, it is possible to disable the special pages outside of one's own global wiki by doing something similar to `miraheze/mw-config` commit e5664995fbb8644f9a80b450b4326194f20f9ddc that is adapted to one's own setup. As for the REST API, before the fix, there wasn't any REST endpoint that allowed one to make writes. Regardless, it is possible to also disable it outside of the global wiki by using `$wgCreateWikiDisableRESTAPI` and `$wgConf` in the configuration for one's own wiki farm..
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Analysis
by VulDB Data Team • 05/14/2024
The vulnerability CVE-2024-34701 affects CreateWiki, a MediaWiki extension developed by Miraheze for managing wiki requests within a wiki farm environment. This extension enables users to request and create new wikis while maintaining centralized control over the wiki creation process. The flaw stems from a misconfiguration in user authentication and authorization mechanisms that allows unauthorized users to impersonate wiki requesters based on matching local user IDs across different wikis within the same farm. This security issue specifically targets the Special:RequestWikiQueue interface where users can view and manage wiki requests.
The technical implementation of this vulnerability occurs when users with matching local IDs on different wikis within the same farm can access the Special:RequestWikiQueue page on a wiki where their local user ID matches the requester's ID from another wiki. This creates a privilege escalation scenario where any user can perform actions typically restricted to the original requester, including modifying request details, approving or rejecting requests, and potentially manipulating the wiki creation process. The vulnerability is classified as a privilege escalation issue under CWE-284, specifically involving insufficient access control mechanisms.
The operational impact of this vulnerability is significant as it allows unauthorized users to manipulate the wiki creation workflow and potentially gain administrative privileges over wiki requests. Attackers could exploit this to approve malicious wiki requests, modify existing requests, or interfere with legitimate wiki creation processes. The vulnerability affects the integrity and confidentiality of the wiki farm's administrative processes, potentially leading to unauthorized wiki creation or modification of existing wiki configurations. This type of vulnerability falls under ATT&CK technique T1078.004 for valid accounts and T1484.001 for trusted relationship abuse.
The fix implemented in commit 02e0f298f8d35155c39aa74193cb7b867432c5b8 addresses the core issue by restricting access to the REST API and special pages to only the wiki configured as the "global wiki" through the `$wgCreateWikiGlobalWiki` setting. This approach ensures that users can only access wiki request management functions from the designated global wiki, preventing cross-wiki privilege escalation. The solution involves disabling access to these functions from all other wikis in the farm, effectively creating a security boundary around the centralized wiki management system. This fix aligns with the principle of least privilege and helps prevent unauthorized access to administrative functions.
The workaround described in the advisory provides administrators with a method to implement similar restrictions without waiting for the official fix. By implementing configuration changes similar to those in commit e5664995fbb8644f9a80b450b4326194f20f9ddc, administrators can manually disable access to special pages outside of the global wiki. Additionally, the REST API can be disabled using the `$wgCreateWikiDisableRESTAPI` configuration variable combined with `$wgConf` settings to ensure that no unauthorized write operations can be performed through the API. These mitigation strategies help protect the wiki farm's integrity while the permanent fix is being deployed across all instances.