CVE-2024-30263 in macro-pdfviewer
Summary
by MITRE • 04/04/2024
macro-pdfviewer is a PDF Viewer Macro for XWiki using Mozilla pdf.js. Users with edit rights can access restricted PDF attachments using the PDF Viewer macro, just by passing the attachment URL as the value of the ``file`` parameter. Users with view rights can access restricted PDF attachments if they are shown on public pages where the PDF Viewer macro is called using the attachment URL instead of its reference. This vulnerability has been patched in version 2.5.1.
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Analysis
by VulDB Data Team • 04/04/2024
The vulnerability identified as CVE-2024-30263 affects the macro-pdfviewer component within XWiki platforms, which utilizes Mozilla pdf.js for PDF rendering capabilities. This PDF Viewer macro is designed to display PDF attachments within XWiki pages, but it contains a critical access control flaw that allows unauthorized users to bypass permission restrictions. The vulnerability specifically targets the handling of attachment URLs within the macro's file parameter processing mechanism, creating a path for privilege escalation through improper authorization checks.
The technical flaw manifests when the PDF Viewer macro processes the file parameter containing an attachment URL. Users with edit rights can exploit this by directly passing attachment URLs to the file parameter, circumventing the normal permission validation that should restrict access to restricted PDF attachments. This issue is particularly concerning because it operates at the application logic level where access controls should be enforced, creating a direct pathway for unauthorized information disclosure. The vulnerability exists in the macro's URL handling and access validation routines, which fail to properly verify user permissions before allowing PDF rendering operations.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially compromise sensitive data within XWiki environments. Users with view rights can access restricted PDF attachments when these documents are displayed on public pages where the macro is invoked using direct attachment URLs rather than reference identifiers. This creates a scenario where sensitive documents that should be restricted to authorized users become accessible to anyone who can view public pages containing the vulnerable macro calls. The vulnerability affects both authenticated and unauthenticated access patterns, making it particularly dangerous in environments where public pages display restricted content.
Organizations using XWiki platforms with the affected macro-pdfviewer version face significant security risks, including potential data breaches and unauthorized access to confidential information. The vulnerability allows attackers to bypass standard access control mechanisms through a simple parameter manipulation attack, making it easily exploitable. Security teams should immediately assess their XWiki installations to identify instances of the vulnerable macro-pdfviewer component and implement immediate mitigation measures. The patched version 2.5.1 addresses the core access control flaw by implementing proper authorization checks before processing attachment URLs through the file parameter.
This vulnerability aligns with CWE-284 Access Control Issues, specifically addressing improper access control mechanisms that allow unauthorized access to restricted resources. The flaw demonstrates a classic privilege escalation pattern where a macro component fails to properly validate user permissions before executing operations that should be restricted. From an ATT&CK framework perspective, this vulnerability maps to T1078 Valid Accounts and T1566 Phishing techniques, as it allows attackers to leverage existing valid accounts to access restricted content through macro manipulation. The security implications extend to data loss prevention and information governance, as unauthorized access to restricted PDF attachments could expose sensitive business information, intellectual property, or personal data. Organizations should consider implementing additional monitoring for unusual macro usage patterns and ensure proper access control configurations are in place to prevent similar vulnerabilities from occurring in other components of their XWiki platform.