CVE-2024-33879 in Virto Bulk File Download for SharePoint 2019
Summary
by MITRE • 06/24/2024
An issue was discovered in VirtoSoftware Virto Bulk File Download 5.5.44 for SharePoint 2019. The Virto.SharePoint.FileDownloader/Api/Download.ashx isCompleted method allows arbitrary file download and deletion via absolute path traversal in the path parameter.
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Analysis
by VulDB Data Team • 06/27/2024
The vulnerability identified as CVE-2024-33879 affects VirtoSoftware Virto Bulk File Download version 5.5.44 specifically within SharePoint 2019 environments. This security flaw resides in the Virto.SharePoint.FileDownloader/Api/Download.ashx endpoint's isCompleted method which processes file download operations. The vulnerability stems from inadequate input validation and path handling mechanisms that fail to properly sanitize user-supplied path parameters, creating a critical path traversal vulnerability that can be exploited by unauthorized actors to access arbitrary files on the server filesystem.
The technical implementation of this vulnerability allows attackers to manipulate the path parameter through absolute path traversal techniques, enabling them to bypass normal file access controls and retrieve files that should remain protected. This flaw operates at the filesystem level where the application does not properly validate or restrict the file paths provided by users, allowing malicious actors to traverse directories beyond the intended scope of file access. The vulnerability specifically affects the isCompleted method within the Download.ashx handler, which processes requests for file download operations and lacks proper authorization checks or path validation mechanisms.
From an operational perspective, this vulnerability presents a severe risk to organizations utilizing SharePoint 2019 with the affected Virto Bulk File Download module. Attackers could potentially access sensitive documents, configuration files, application binaries, and other system resources that should remain restricted to authorized personnel only. The impact extends beyond simple data theft to include potential system compromise through access to application configuration files or database connection strings that might be stored in accessible locations within the filesystem. This vulnerability aligns with CWE-22 Path Traversal and CWE-23 Relative Path Traversal, representing a classic example of inadequate input sanitization that allows attackers to manipulate file access patterns.
The exploitation of this vulnerability follows established attack patterns documented in the MITRE ATT&CK framework under techniques related to credential access and privilege escalation. Attackers can leverage this flaw to perform reconnaissance activities by accessing system files and configuration data, potentially identifying additional attack vectors or system weaknesses within the SharePoint environment. The vulnerability also represents a significant concern for compliance requirements, as it could lead to data breaches that violate regulations such as GDPR, HIPAA, or other data protection frameworks that mandate proper access controls and data protection measures.
Organizations should immediately implement mitigations including input validation controls that sanitize all path parameters, restrict access to the vulnerable endpoint through network segmentation, and implement proper authorization checks before allowing file operations. The recommended approach involves deploying application-level firewalls or web application firewalls that can detect and block malicious path traversal attempts, while also ensuring that the affected module is updated to a patched version that properly validates file paths. Additionally, system administrators should conduct thorough access reviews to limit the permissions of the SharePoint application pool identity and implement proper logging mechanisms to detect unauthorized file access attempts that could indicate exploitation of this vulnerability.