CVE-2022-41932 - XWiki Platform: Crafting User Identifiers to Create Schemas and Fill Tables, Causing Database Performance Degradation

XWiki Platform, a popular and versatile wiki platform, has recently discovered a vulnerability designated as CVE-2022-41932. By merely utilizing a specially crafted user identifier in the login form, an attacker can force XWiki to generate excessive schemas and populate them with tables. As a result, the performance of the underlying database might suffer significantly. XWiki developers have issued a patch for this vulnerability in versions 13.10.8, 14.6RC1, and 14.4.2, urging users to upgrade as soon as possible. Currently, there are no workarounds for this issue.

Exploit Details

The vulnerability lies in the process of handling a user's identifier within the login function. By injecting a carefully crafted user identifier, an attacker can exploit the feature that manages schema creation and triggers the generation of a vast number of new schemas. Subsequently, the attacker can populate these schemas with tables, ultimately affecting the performance of the affected database.

To illustrate the exploit, let's assume that the expected identifier format is "username@domain.com". An attacker can inject a crafted user identifier, such as "username@evil1.evil2.evil3.domain.com". This way, the attacker can manipulate the login function to create schemas and fill them with tables unnecessarily.

Code Snippet

# Sample code illustrating the injection of a crafted user identifier into the login form

def craft_user_identifier(username: str, domain: str, injection: str):
    # Combine the username and domain with the crafted injection
    user_identifier = f"{username}@{injection}.{domain}"
    return user_identifier

# Example usage
crafted_identifier = craft_user_identifier("victim", "example.com", "evil1.evil2.evil3")
print(crafted_identifier) # Outputs: victim@evil1.evil2.evil3.example.com

Original References

- XWiki Platform: https://www.xwiki.org/xwiki/bin/view/Main/WebHome
- CVE-2022-41932: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-41932
- XWiki Security Advisory: https://www.xwiki.org/xwiki/bin/view/Security/Data/XWIKI-19099

Mitigation

In order to mitigate the risk associated with CVE-2022-41932, users should upgrade their XWiki Platform installations to version 13.10.8, 14.6RC1, or 14.4.2, whichever is applicable. The updated versions contain the necessary patches that address the vulnerability. Further information on upgrading the XWiki Platform can be found in the official documentation: https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Upgrade/

As of now, no viable workarounds are available for this issue. The best course of action is to update your XWiki instance promptly to safeguard your wiki environment and maintain optimal database performance.

Timeline

Published on: 11/23/2022 21:15:00 UTC
Last modified on: 11/30/2022 17:46:00 UTC