CVE-2008-4216 in Safari
Summary
by MITRE
The plug-in interface in WebKit in Apple Safari before 3.2 does not prevent plug-ins from accessing local URLs, which allows remote attackers to obtain sensitive information via vectors that "launch local files."
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Analysis
by VulDB Data Team • 08/21/2019
The vulnerability described in CVE-2008-4216 represents a critical security flaw in the WebKit rendering engine used by Apple Safari browsers prior to version 3.2. This issue stems from insufficient sandboxing mechanisms within the browser's plugin architecture that fails to properly isolate plugin execution contexts from local system resources. The flaw specifically affects how the browser handles plugin interfaces and their interaction with local file systems, creating a pathway for malicious actors to exploit the trust relationship between browser components and system resources.
The technical implementation of this vulnerability lies in the improper handling of local URL access within Safari's plugin interface. When plugins are executed, they should be restricted from directly accessing local file systems or network resources without explicit user consent and proper authorization checks. However, the WebKit implementation in affected Safari versions allowed plugins to bypass these security boundaries and access local files through what the description refers to as "launch local files" vectors. This represents a classic sandbox escape mechanism where the boundary between trusted browser components and untrusted plugin content becomes porous.
The operational impact of this vulnerability is significant as it enables remote attackers to potentially access sensitive information stored on the local system. Attackers could craft malicious web pages that, when loaded in affected Safari browsers, would allow plugins to read local files that should normally be protected from web-based access. This includes potentially sensitive data such as user credentials, configuration files, personal documents, or other system information that could be valuable for further exploitation or identity theft. The vulnerability essentially undermines the fundamental security principle that web content should not have unrestricted access to local system resources.
This flaw aligns with CWE-264, which addresses permissions, privileges, and access controls, and demonstrates how inadequate sandboxing can lead to privilege escalation attacks. The vulnerability also relates to ATT&CK technique T1059.007 for command and scripting interpreter, as it enables attackers to potentially execute local commands or access system resources through compromised plugin interfaces. Organizations using affected Safari versions face heightened risk of data breaches and system compromise, particularly in environments where users may encounter malicious web content. The vulnerability highlights the importance of proper input validation and access control enforcement in browser plugin architectures, as well as the necessity of maintaining up-to-date security patches to protect against known exploitation vectors.
The mitigation strategy for this vulnerability requires immediate patching of Safari browsers to version 3.2 or later, which includes enhanced sandboxing controls and proper URL access restrictions for plugin interfaces. Additionally, system administrators should implement network-based security controls such as web application firewalls and content filtering solutions to detect and block potentially malicious web content. Regular security assessments of browser configurations and plugin management practices should be conducted to ensure that similar vulnerabilities are not present in other browser components or third-party extensions. The incident underscores the critical importance of maintaining robust browser security boundaries and demonstrates how seemingly minor implementation flaws in core browser components can result in significant information disclosure risks.