CVE-2017-7503 in JBoss Enterprise Application Platform
Summary
by MITRE
It was found that the Red Hat JBoss EAP 7.0.5 implementation of javax.xml.transform.TransformerFactory is vulnerable to XXE. An attacker could use this flaw to launch DoS or SSRF attacks, or read files from the server where EAP is deployed.
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Analysis
by VulDB Data Team • 12/25/2020
The vulnerability identified as CVE-2017-7503 affects the Red Hat JBoss Enterprise Application Platform version 7.0.5 through the javax.xml.transform.TransformerFactory implementation, representing a significant security weakness that exposes systems to multiple attack vectors. This flaw resides within the XML processing capabilities of the application server, specifically in how it handles external entity references during XML transformation operations. The vulnerability stems from insufficient input validation and improper handling of external entity declarations, creating an avenue for malicious actors to manipulate XML parsing behavior.
The technical implementation of this vulnerability allows attackers to exploit the TransformerFactory's processing of XML documents through XML External Entity (XXE) attacks. When the system processes XML input containing malicious external entity references, it can be coerced into making unauthorized network connections or accessing local files on the server. The vulnerability specifically targets the javax.xml.transform package which is part of the standard java.xml.transform API, making it a fundamental component that applications rely upon for XML processing. This flaw operates at the XML parser level where external entities are resolved without proper sanitization of input data, enabling attackers to construct payloads that trigger unintended behavior.
The operational impact of CVE-2017-7503 extends beyond simple data exposure to encompass denial of service conditions and server-side request forgery attacks. Attackers can leverage this vulnerability to consume excessive system resources through recursive entity expansion, leading to service disruption and potential system crashes. Additionally, the flaw enables unauthorized file access patterns that could allow attackers to read sensitive server files including configuration data, application source code, or database credentials stored on the filesystem. The combination of these attack vectors creates a comprehensive threat landscape where adversaries can perform reconnaissance, escalate privileges, and potentially gain complete control over the affected server environment. This vulnerability particularly affects systems running JBoss EAP 7.0.5 where XML processing is utilized, making it a critical concern for enterprise applications that handle XML data inputs.
The vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and maps to several ATT&CK techniques including T1059.007 (Command and Scripting Interpreter: Python) through potential exploitation of XML processing, T1068 (Exploitation for Privilege Escalation) when accessing protected files, and T1499.004 (Endpoint Denial of Service) through DoS attack capabilities. Organizations should implement immediate mitigations including disabling external entity resolution in XML parsers, implementing proper input validation for all XML processing operations, and restricting network access to prevent SSRF attacks. The recommended approach involves configuring the TransformerFactory to disable external entity processing, applying the latest security patches from Red Hat, and conducting thorough code reviews to identify all XML processing points within applications. Additionally, network segmentation and monitoring should be implemented to detect suspicious XML processing activities and prevent unauthorized file access attempts that could exploit this vulnerability.