CVE-2011-2357 in Android
Summary
by MITRE
Cross-application scripting vulnerability in the Browser URL loading functionality in Android 2.3.4 and 3.1 allows local applications to bypass the sandbox and execute arbitrary Javascript in arbitrary domains by (1) causing the MAX_TAB number of tabs to be opened, then loading a URI to the targeted domain into the current tab, or (2) making two startActivity function calls beginning with the targeted domain s URI followed by the malicious Javascript while the UI focus is still associated with the targeted domain.
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Analysis
by VulDB Data Team • 11/05/2024
The vulnerability described in CVE-2011-2357 represents a significant cross-application scripting flaw within the Android browser component that fundamentally undermines the operating system's security model. This vulnerability exists in Android versions 2.3.4 and 3.1, specifically targeting the browser URL loading functionality and exploiting a weakness in how the system handles tab management and domain context switching. The flaw allows malicious applications to bypass the traditional sandboxing mechanisms that separate applications from each other and from the core system, creating a pathway for unauthorized code execution. The vulnerability is particularly concerning because it enables local applications to execute arbitrary JavaScript code within the context of arbitrary domains, effectively allowing attackers to perform actions that should be restricted to the browser's own security boundaries.
The technical exploitation of this vulnerability relies on two distinct but related attack vectors that leverage the browser's tab management system and UI focus mechanisms. The first vector involves opening the maximum number of tabs allowed by the system, then loading a URI to a targeted domain into the current tab, which creates a specific context that can be manipulated to execute malicious code. The second vector employs two consecutive startActivity function calls where the first call begins with the targeted domain's URI followed by malicious JavaScript, taking advantage of the fact that the user interface focus remains associated with the targeted domain during the execution sequence. Both methods exploit the underlying assumption that the browser's security context can be manipulated through legitimate system calls, bypassing the normal cross-domain security restrictions that should prevent one application from executing code in the context of another domain. This vulnerability directly relates to CWE-79 which describes Cross-Site Scripting (XSS) vulnerabilities, and more specifically to CWE-94 which addresses Improper Control of Generation of Code, as it allows for arbitrary code execution through the manipulation of JavaScript execution contexts.
The operational impact of this vulnerability extends far beyond simple code execution, as it fundamentally compromises the integrity of the Android security model and creates opportunities for sophisticated attacks. Attackers can leverage this vulnerability to perform actions such as stealing user credentials, accessing sensitive data, redirecting users to malicious websites, or even executing privilege escalation attacks that could compromise the entire device. The ability to execute JavaScript in arbitrary domains means that attackers can potentially exploit known vulnerabilities in web applications that users might be visiting, or they could create convincing phishing attacks that appear to originate from legitimate domains. The vulnerability affects not just individual users but also enterprise environments where Android devices are commonly used, as it could be exploited to gain unauthorized access to corporate networks or steal sensitive business information. This type of vulnerability is particularly dangerous in mobile environments where users may not be as security-aware as in desktop environments, and where the attack surface is expanded by the integration of multiple applications and services.
Mitigation strategies for this vulnerability require both immediate system-level patches and careful application development practices to prevent exploitation. The primary solution involves applying the security patches released by Google that address the core browser functionality and tab management issues that enable this attack. Organizations should also implement application whitelisting policies that restrict which applications can make startActivity calls and monitor for suspicious activity patterns that might indicate exploitation attempts. Network-level monitoring should be enhanced to detect unusual patterns of tab creation or URL loading that could indicate exploitation attempts. Developers should be educated about the proper use of startActivity functions and the security implications of manipulating UI focus contexts. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1059.007 for JavaScript execution and T1068 for local privilege escalation, making it a significant concern for security teams implementing threat detection and response strategies. Additionally, organizations should consider implementing mobile device management solutions that can enforce security policies and monitor for suspicious application behavior that might indicate exploitation of this vulnerability. The vulnerability also highlights the importance of proper input validation and context management in browser implementations, as it demonstrates how seemingly legitimate system functions can be abused to create security breaches that bypass traditional sandboxing mechanisms.