CVE-2017-14527 in Documentum Webtop
Summary
by MITRE
Multiple XML external entity (XXE) vulnerabilities in the OpenText Documentum Webtop 6.8.0160.0073 allow remote authenticated users to list the contents of arbitrary directories, read arbitrary files, cause a denial of service, or, on Windows, obtain Documentum user hashes via a (1) crafted DTD, involving unspecified XML structures in a request to xda/com/documentum/ucf/server/transport/impl/GAIRConnector or crafted XML file in a MediaProfile file (2) import or (3) check in.
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Analysis
by VulDB Data Team • 11/20/2019
The CVE-2017-14527 vulnerability represents a critical XML external entity processing flaw in OpenText Documentum Webtop 6.8.0160.0073 that exposes multiple attack vectors for authenticated remote adversaries. This vulnerability falls under the CWE-611 weakness category, specifically targeting insecure XML processing mechanisms that fail to properly validate and sanitize external entity references. The flaw exists within the application's handling of XML data structures, particularly when processing requests to the GAIRConnector endpoint and during MediaProfile file operations, creating a pathway for attackers to manipulate the XML parser behavior through crafted external entity declarations.
The technical exploitation of this vulnerability occurs through two primary attack vectors involving XML document manipulation. The first vector leverages a crafted DTD (Document Type Definition) file that references external entities, enabling attackers to traverse the file system and enumerate directory contents on the target server. The second vector involves importing or checking in maliciously crafted XML files within MediaProfile configurations, which allows for arbitrary file reading capabilities. These attack methods specifically target the XML parsing functionality within the UCF (Unified Content Framework) server transport implementation, where the application fails to properly restrict external entity resolution during XML processing operations.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential system compromise and service disruption. Remote authenticated users can leverage these XXE flaws to access sensitive system files, potentially including configuration data, user credentials, or application source code. On Windows systems, the vulnerability enables attackers to obtain Documentum user hashes, which represent a significant compromise of authentication security. Additionally, the vulnerability can be exploited to cause denial of service conditions by consuming excessive system resources through malformed XML entity references. This creates a multi-dimensional threat landscape where attackers can perform reconnaissance, escalate privileges, and disrupt business operations simultaneously.
Organizations should implement multiple layers of defense to mitigate this vulnerability, including disabling external entity resolution in XML parsers, implementing strict input validation for all XML processing operations, and restricting file system access for application processes. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter usage and T1083 for file and directory discovery, highlighting the reconnaissance and privilege escalation potential. Security measures should focus on network segmentation to limit authenticated access, regular security assessments of XML processing components, and implementation of web application firewalls that can detect and block malicious XML entity references. The vulnerability underscores the importance of proper XML security configuration and demonstrates how seemingly minor parsing flaws can create significant security breaches in enterprise content management systems.