CVE-2019-12366 in App
Summary
by MITRE
The Nine application through 4.5.3a for Android allows XSS via an event attribute and arbitrary file loading via a src attribute, if the application has the READ_EXTERNAL_STORAGE permission.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability identified as CVE-2019-12366 affects the Nine Android application version 4.5.3a and earlier, presenting a critical security risk through cross-site scripting and arbitrary file loading capabilities. This flaw manifests when the application possesses the READ_EXTERNAL_STORAGE permission, creating an attack surface that adversaries can exploit to compromise user data and system integrity. The vulnerability stems from insufficient input validation and sanitization mechanisms within the application's processing of event attributes and source attributes, particularly when handling external file references.
The technical implementation of this vulnerability involves two primary attack vectors that together create a dangerous exploitation scenario. The first vector allows cross-site scripting through event attributes, where malicious input can be injected into event handlers that are subsequently executed within the application's context. This represents a classic XSS vulnerability that falls under CWE-79, which specifically addresses cross-site scripting flaws in web applications and mobile applications. The second vector enables arbitrary file loading through src attributes, permitting attackers to reference and load external files from the device's storage system. When combined with the READ_EXTERNAL_STORAGE permission, this creates an environment where attackers can access and potentially execute malicious content from external storage locations, effectively bypassing normal security boundaries.
The operational impact of this vulnerability extends beyond simple data theft or display manipulation. Attackers can leverage the XSS capability to steal session cookies, perform unauthorized actions on behalf of users, or redirect them to malicious websites that can further compromise their devices. The arbitrary file loading component amplifies this threat by allowing potential code execution from external storage, which could include malware or additional malicious payloads. This vulnerability particularly affects users who have granted the application broad storage permissions, making it a significant concern for mobile security. The attack surface is further expanded through the potential for privilege escalation, as the combination of these vulnerabilities can enable attackers to gain deeper access to the device's file system and potentially other applications.
Mitigation strategies for this vulnerability require immediate attention from both application developers and end users. Application developers should implement comprehensive input validation and sanitization mechanisms, particularly for attributes that handle event handlers and source references. The implementation of Content Security Policy headers and proper escaping of user-supplied data can significantly reduce the risk of XSS exploitation. Additionally, developers should avoid unnecessary use of the READ_EXTERNAL_STORAGE permission and implement proper file access controls when such permissions are required. From a user perspective, it is essential to review application permissions and revoke unnecessary storage access. The vulnerability also highlights the importance of regular security audits and code reviews, particularly focusing on input handling and permission management. Organizations should consider implementing mobile application security testing as part of their development lifecycle, following frameworks such as OWASP Mobile Security Project guidelines. This vulnerability demonstrates the critical importance of secure coding practices and proper permission management in mobile applications, aligning with ATT&CK technique T1068 which addresses local privilege escalation and T1555 which covers credential access through application vulnerabilities. The remediation process should include thorough testing of input validation mechanisms and comprehensive security assessments to ensure that similar vulnerabilities do not exist in other application components.