CVE-2011-2139 in Flash Player
Summary
by MITRE
Adobe Flash Player before 10.3.183.5 on Windows, Mac OS X, Linux, and Solaris and before 10.3.186.3 on Android, and Adobe AIR before 2.7.1 on Windows and Mac OS X and before 2.7.1.1961 on Android, allows remote attackers bypass the Same Origin Policy and obtain sensitive information via unspecified vectors.
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Analysis
by VulDB Data Team • 11/17/2021
Adobe Flash Player and Adobe AIR implementations contained a critical security flaw that enabled remote attackers to circumvent the fundamental Same Origin Policy mechanism designed to protect web applications from cross-site scripting attacks. This vulnerability affected multiple platforms including Windows, Mac OS X, Linux, Solaris, and Android systems, with different version thresholds for each platform. The flaw allowed attackers to execute unauthorized data access operations that should have been restricted by web browser security models, effectively breaking down the isolation barriers between different web domains and applications.
The technical nature of this vulnerability stemmed from improper handling of cross-domain resource access within the Flash Player runtime environment. When Flash applications attempted to access resources from different origins, the security checks that should have prevented such access were either bypassed entirely or inadequately enforced. This weakness specifically targeted the security model that prevents web pages from accessing data from different domains without explicit permission, which is a cornerstone of modern web security architecture. The vulnerability was categorized under CWE-284, which addresses improper access control mechanisms, and directly undermined the browser sandboxing principles that protect users from malicious content.
The operational impact of this vulnerability was severe and far-reaching, as it enabled attackers to perform data exfiltration from victim machines without requiring any user interaction or privileges beyond standard web browsing capabilities. Attackers could exploit this flaw to access sensitive information such as cookies, session tokens, and other user data that should have remained isolated between different web origins. This capability significantly increased the risk of credential theft, session hijacking, and other advanced persistent threats that could compromise user accounts and corporate networks. The vulnerability's presence across multiple operating systems and platforms made it particularly dangerous as it could be exploited against diverse user bases regardless of their device type or operating environment.
Security professionals recommended immediate patching of affected systems as the primary mitigation strategy, with organizations implementing network monitoring to detect potential exploitation attempts. The vulnerability demonstrated the critical importance of maintaining up-to-date software components and highlighted the risks associated with legacy Flash Player installations. Organizations should have implemented additional security controls including web application firewalls, content filtering solutions, and browser security enhancements to provide defense-in-depth measures. The incident underscored the necessity of proper access control implementation and the importance of regularly auditing security mechanisms within runtime environments that execute untrusted code, aligning with ATT&CK techniques that focus on privilege escalation and credential access through browser-based exploits.