CVE-2022-31167 is a security vulnerability classified under CWE-285 (Improper Authorization) and CWE-862 (Missing Authorization) affecting the XWiki Platform, a widely used generic wiki platform. The vulnerability arises from a flaw in the security cache mechanism of the XWiki Platform Security Parent POM, which manages security APIs for the platform. Specifically, in versions starting from 5.0 up to but not including 12.10.11, 13.10.1, and 13.4.6, the security cache incorrectly stores authorization rules for both documents and spaces under the same cache entry when they share the same name pattern (e.g., Page1.Page2). This caching bug allows an attacker to overwrite the access rights of a space or document by creating a page with the same name as the space and triggering a rights check on the newly created page first. Consequently, the cached rights for one entity (space or document) can be improperly applied to the other, leading to unauthorized access or privilege escalation. This flaw undermines the integrity of the authorization process, potentially allowing users to gain access to restricted content or perform unauthorized actions within the wiki environment. The issue has been addressed and patched in versions 12.10.11, 13.10.1, and 13.4.6 of the XWiki Platform. No known workarounds exist, and no exploits have been reported in the wild to date. The vulnerability requires the attacker to have the ability to create pages within the affected XWiki instance, implying some level of authenticated access or user interaction is necessary to exploit the flaw.

For European organizations utilizing vulnerable versions of the XWiki Platform, this vulnerability poses a significant risk to the confidentiality and integrity of their internal documentation and collaboration environments. Unauthorized access to sensitive documents or spaces could lead to data leakage, intellectual property theft, or manipulation of critical information. Since XWiki is often used for knowledge management, project documentation, and internal communication, exploitation could disrupt business operations and erode trust in organizational information systems. The improper authorization could also facilitate privilege escalation within the wiki, enabling attackers to perform administrative actions or further lateral movement within the network. Given the collaborative nature of XWiki deployments, the scope of impact could extend to multiple departments or teams, amplifying the potential damage. Although no known exploits exist currently, the absence of workarounds and the ease of triggering the cache overwrite through page creation make timely patching essential to prevent exploitation. The impact is particularly relevant for sectors with strict data protection requirements, such as finance, healthcare, and government agencies in Europe, where unauthorized data exposure could lead to regulatory penalties and reputational harm.

To effectively mitigate CVE-2022-31167, European organizations should prioritize upgrading their XWiki Platform instances to the patched versions 12.10.11, 13.10.1, or 13.4.6 as soon as possible. Since no workarounds are available, patching is the primary defense. Additionally, organizations should audit user permissions to ensure that only trusted users have the ability to create or modify pages, thereby reducing the attack surface. Implementing strict access controls and monitoring page creation activities can help detect anomalous behavior indicative of exploitation attempts. Organizations should also consider deploying web application firewalls (WAFs) with custom rules to monitor and potentially block suspicious requests related to page creation or rights checking within the XWiki environment. Regularly reviewing and tightening authorization policies within the wiki can further minimize risks. Finally, maintaining comprehensive logging and alerting on security-related events in XWiki will aid in early detection and response to any exploitation attempts.