CVE-2011-0167 in Safari
Summary
by MITRE
The windows functionality in WebKit in Apple Safari before 5.0.4 allows remote attackers to bypass the Same Origin Policy, and force the upload of arbitrary local files from a client computer, via a crafted web site.
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Analysis
by VulDB Data Team • 06/14/2025
The vulnerability identified as CVE-2011-0167 represents a critical security flaw in Apple Safari's WebKit rendering engine that existed prior to version 5.0.4. This issue fundamentally compromised the browser's security model by enabling malicious web sites to circumvent the essential Same Origin Policy mechanism that protects web applications from unauthorized cross-origin data access. The vulnerability specifically targeted the window functionality within WebKit, which is responsible for managing browser windows and their associated security boundaries.
The technical implementation of this flaw allowed remote attackers to exploit a weakness in how Safari handled file access permissions and cross-origin restrictions. Through careful crafting of malicious web content, attackers could manipulate the browser's security controls to force the upload of arbitrary local files from a user's computer without their knowledge or consent. This capability directly violates fundamental web security principles and represents a significant bypass of client-side security measures. The vulnerability exploited the underlying architecture of WebKit's window handling mechanisms, specifically targeting how the browser managed file system access and origin-based security boundaries.
Operationally, this vulnerability created severe risks for end users and organizations as it enabled attackers to harvest sensitive local files from compromised systems. The ability to force arbitrary file uploads meant that attackers could potentially access personal documents, configuration files, browser data, and other locally stored information without user interaction or explicit permission. This type of vulnerability falls under the category of client-side attacks that can be executed through web-based delivery mechanisms, making it particularly dangerous in environments where users frequently browse untrusted websites. The impact extends beyond simple data theft to potentially enable further exploitation through the access to local system resources and sensitive information.
Security professionals should note that this vulnerability aligns with CWE-284, which addresses improper access control issues, and relates to ATT&CK technique T1059.007 for web shell execution and T1566 for phishing attacks that leverage browser vulnerabilities. The flaw demonstrates how browser-based security mechanisms can be subverted to create unauthorized access to local system resources, representing a classic example of privilege escalation through client-side exploitation. Organizations should prioritize immediate patching of affected Safari versions and implement additional browser security measures such as content security policies and enhanced user education about browsing risks. Network monitoring should be enhanced to detect suspicious file transfer activities that might indicate exploitation attempts, while endpoint protection solutions should be configured to block potentially malicious file upload operations from web browsers.
The vulnerability highlights the importance of maintaining up-to-date browser software and demonstrates how seemingly isolated browser functionality can have far-reaching security implications when implemented incorrectly. Security teams should consider this as part of broader browser security assessments and ensure that all web-based applications and services are protected against similar cross-origin access violations. Regular security audits of browser configurations and implementation of security-focused development practices can help prevent similar vulnerabilities from emerging in the future.