CVE-2016-2340 in Data Services
Summary
by MITRE
The AMF framework in Granite Data Services 3.1.1-SNAPSHOT allows remote authenticated users to read arbitrary files, send TCP requests to intranet servers, or cause a denial of service via an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.
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Analysis
by VulDB Data Team • 11/12/2024
The vulnerability identified as CVE-2016-2340 represents a critical XML External Entity (XXE) flaw within the AMF framework of Granite Data Services version 3.1.1-SNAPSHOT. This issue stems from the framework's inadequate handling of XML external entity declarations, creating a pathway for malicious actors to exploit the system through carefully crafted XML payloads. The vulnerability specifically affects authenticated users who can leverage the XXE mechanism to perform unauthorized operations against the underlying system infrastructure. The flaw exists in the application's XML processing logic where external entity declarations are not properly validated or sanitized, allowing attackers to reference external resources and execute malicious operations.
The technical implementation of this vulnerability enables attackers to perform several dangerous operations through a single authenticated session. Remote authenticated users can exploit the XXE vulnerability to read arbitrary files from the server filesystem, potentially accessing sensitive configuration files, database credentials, or application source code. Additionally, the vulnerability permits attackers to send TCP requests to intranet servers that are otherwise not directly accessible from the internet, effectively bypassing network segmentation controls and enabling internal network reconnaissance. The XXE mechanism also allows for denial of service conditions by consuming excessive system resources through malformed entity references that trigger resource exhaustion during XML parsing operations.
This vulnerability directly maps to CWE-611, which specifically addresses Improper Restriction of XML External Entity Reference, and aligns with ATT&CK technique T1213.002 for Data from Information Repositories. The impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to perform lateral movement within network environments and establish persistent access patterns. The authenticated nature of the vulnerability means that attackers must first obtain valid credentials, but once achieved, the attack surface expands significantly. The XXE vulnerability essentially allows attackers to manipulate the XML parser behavior to reference external entities that can be configured to access local files, internal network services, or even external malicious servers.
Organizations affected by this vulnerability should immediately implement mitigations including disabling external entity processing in XML parsers, implementing strict input validation for all XML content, and applying the latest available patches from Granite Data Services. Network segmentation controls should be reviewed to limit the potential impact of successful XXE exploitation, particularly concerning internal network access. The implementation of web application firewalls with XXE detection capabilities can provide additional layers of protection. Security monitoring should be enhanced to detect unusual file access patterns or outbound network connections that may indicate XXE exploitation attempts. Regular security assessments of XML processing components and comprehensive input validation testing should be conducted to prevent similar vulnerabilities from emerging in the future.