CVE-2016-0288 in Security AppScan
Summary
by MITRE
IBM Security AppScan Standard 8.7.x, 8.8.x, and 9.x before 9.0.3.2 and Security AppScan Enterprise allow remote authenticated users to read arbitrary files via an XML document containing an 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 • 08/21/2022
This vulnerability resides within IBM Security AppScan Standard and Enterprise products, specifically affecting versions 8.7.x through 9.0.3.1. The flaw represents a classic XML External Entity processing weakness that allows authenticated attackers to exploit file disclosure capabilities through carefully crafted XML documents. The vulnerability stems from insufficient input validation and sanitization of XML content, enabling attackers to manipulate the XML parser behavior by introducing external entity declarations that reference local files on the server system. This XXE implementation permits attackers to access arbitrary files that the application process has read permissions for, potentially exposing sensitive configuration files, database credentials, or other confidential data stored on the server.
The technical exploitation occurs when the application processes XML input containing external entity declarations that reference local file paths through entity references. Attackers can leverage this by constructing XML documents that declare external entities pointing to system files such as /etc/passwd, configuration files, or other sensitive resources. The vulnerability specifically affects the XML processing components within the security scanning framework, where the application's XML parser fails to properly validate or sanitize external entity references. This weakness aligns with CWE-611, which categorizes improper restriction of XML external entity references, and represents a direct violation of secure coding practices for XML processing. The attack vector requires authentication since the vulnerability exists within the application's legitimate processing pathways, making it more difficult to detect compared to unauthenticated attacks.
The operational impact of this vulnerability extends beyond simple file disclosure, as it can potentially expose critical system information that could aid in further exploitation attempts. Attackers could access configuration files that might contain database connection strings, API keys, or other sensitive parameters that could be used to escalate privileges or compromise additional systems. The vulnerability affects both the standard and enterprise editions of the security scanning tool, creating a potential backdoor through which attackers could access the scanning infrastructure itself. This creates a particularly concerning scenario where an attacker could potentially access the very tools designed to detect and prevent security issues, effectively undermining the security posture of organizations relying on these products for vulnerability assessment. The impact is further amplified by the fact that these applications are often deployed in enterprise environments where they have elevated privileges and access to sensitive network resources.
Organizations should immediately apply the vendor-provided patches for IBM Security AppScan Standard and Enterprise versions 9.0.3.2 and later, as these releases contain the necessary fixes to address the XXE vulnerability. The mitigation strategy should include implementing strict XML input validation and sanitization mechanisms, particularly for any XML processing components within the application. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts. Additionally, regular security assessments should be conducted to identify and remediate similar vulnerabilities in other applications and systems. The fix typically involves updating the XML parser configuration to disable external entity resolution or properly validate and sanitize all external entity declarations. This vulnerability demonstrates the importance of following the principle of least privilege and implementing robust input validation controls, particularly for applications that process user-supplied data. The issue also highlights the need for regular security updates and patch management processes, as this vulnerability has existed for several years and affects multiple versions of the product. Security teams should also consider implementing monitoring and alerting mechanisms to detect potential exploitation attempts through unusual file access patterns or XML processing activities.