CVE-2022-36091

XWiki Platform Web Templates are templates for XWiki Platform, a generic wiki platform. Through the suggestion feature, string and list properties of objects the user shouldnt have access to can be accessed in versions prior to 13.10.4 and 14.2. This includes private personal information like email addresses and salted password hashes of registered users but also other information stored in properties of objects. Sensitive configuration fields like passwords for LDAP or SMTP servers could be accessed. By exploiting an additional vulnerability, this issue can even be exploited on private wikis at least for string properties. The issue is patched in version 13.10.4 and 14.2. Password properties are no longer displayed and rights are checked for other properties. A workaround is available. The template file suggest.vm can be replaced by a patched version without upgrading or restarting XWiki unless it has been overridden, in which case the overridden template should be patched, too. This might need adjustments for older versions, though.

Weakness

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Affected Software

Extended Description

Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user’s privileges and any permissions or other access-control specifications that apply to the resource. When access control checks are not applied, users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.

Potential Mitigations

• Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
• Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
• For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
• One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/665.html

References

• https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-599v-w48h-rjrm
• https://jira.xwiki.org/browse/XWIKI-18849