CVE-2022-36093 in XWiki Platform Web Templates
Summary
by MITRE • 09/08/2022
XWiki Platform Web Templates are templates for XWiki Platform, a generic wiki platform. By passing a template of the distribution wizard to the xpart template, user accounts can be created even when user registration is disabled. This also circumvents any email verification. Before versions 14.2 and 13.10.4, this can also be exploited on a private wiki, thus potentially giving the attacker access to the wiki. Depending on the configured default rights of users, this could also give attackers write access to an otherwise read-only public wiki. Users can also be created when an external authentication system like LDAP is configured, but authentication fails unless the authentication system supports a bypass/local accounts are enabled in addition to the external authentication system. This issue has been patched in XWiki 13.10.5 and 14.3RC1. As a workaround, one may replace `xpart.vm`, the entry point for this attack, by a patched version from the patch without updating XWiki.
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Analysis
by VulDB Data Team • 10/14/2022
The vulnerability identified as CVE-2022-36093 represents a critical authorization bypass flaw within the XWiki Platform Web Templates system, specifically targeting the distribution wizard template functionality. This issue affects the core wiki platform's user management mechanisms and demonstrates how template processing can be exploited to circumvent fundamental security controls. The vulnerability exists in the xpart template component which serves as an entry point for the attack vector, allowing unauthorized user account creation even when the system has explicitly disabled user registration. This flaw directly violates the principle of least privilege and represents a significant weakness in the platform's access control implementation, as it enables attackers to bypass the intended security boundaries that protect against unauthorized system access.
The technical exploitation of this vulnerability occurs through the manipulation of template parameters passed to the xpart template within the XWiki Platform's distribution wizard functionality. When user registration is disabled, the system should normally prevent any new account creation, but the flaw allows attackers to bypass this restriction by leveraging the template processing mechanism. The vulnerability extends beyond simple account creation to include the circumvention of email verification processes, which represents a complete breakdown in the platform's user authentication and verification workflow. This issue affects both public and private wiki instances, with the potential for attackers to gain unauthorized access to private wikis when exploiting versions prior to 14.2 and 13.10.4. The flaw operates at the template rendering level, where user input is processed through the xpart.vm template without proper authorization checks, creating a direct path for privilege escalation and unauthorized system access.
The operational impact of this vulnerability is substantial, as it can enable attackers to gain persistent access to wiki systems and potentially escalate privileges based on the configured default user rights. In public wikis with read-only access controls, attackers could gain write permissions through the creation of user accounts with elevated privileges, allowing them to modify content and potentially compromise the integrity of the entire wiki platform. The vulnerability becomes particularly dangerous when combined with external authentication systems such as LDAP, as it can create scenarios where attackers can bypass external authentication failures and create local accounts. This creates a complex attack surface where the vulnerability can be exploited even when external authentication mechanisms are properly configured, demonstrating how template-based flaws can undermine the security of integrated authentication systems. The issue affects both the platform's user management and content access control mechanisms, potentially allowing attackers to modify or delete content across multiple wiki instances.
Mitigation strategies for this vulnerability include immediate patching to versions 13.10.5 and 14.3RC1, which contain the necessary security fixes to prevent the template manipulation that enables account creation bypass. Organizations should also implement the workaround of replacing the xpart.vm template file with a patched version without requiring full platform updates, providing immediate protection while maintaining system stability. Security administrators should review and audit existing user accounts to identify any unauthorized access that may have occurred through this vulnerability, particularly focusing on accounts created during the vulnerable period. The vulnerability aligns with CWE-285, which addresses improper authorization in template processing systems, and demonstrates characteristics consistent with ATT&CK technique T1078 for valid accounts and T1566 for social engineering through template manipulation. Organizations should also consider implementing additional monitoring around user account creation events and template processing activities to detect potential exploitation attempts, as this vulnerability could be used as part of broader attack campaigns targeting wiki platforms and collaboration systems.