CVE-2011-0244 in Safari
Summary
by MITRE
WebKit in Apple Safari before 5.0.6 allows user-assisted remote attackers to read arbitrary files via vectors related to improper canonicalization of URLs within RSS feeds.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability identified as CVE-2011-0244 represents a critical security flaw in Apple Safari's WebKit rendering engine that existed prior to version 5.0.6. This issue stems from improper canonicalization of URLs within RSS feed processing, creating a pathway for remote attackers to potentially access sensitive files on affected systems. The vulnerability specifically targets how Safari handles URL normalization when processing RSS content, which can lead to unexpected file access patterns that bypass normal security boundaries. This flaw demonstrates the complexity of web browser security implementations where seemingly benign RSS feed processing can become a vector for unauthorized file access.
The technical implementation of this vulnerability involves WebKit's handling of URL canonicalization within RSS feed contexts. When Safari processes RSS feeds containing malformed or specially crafted URLs, the browser's URL resolution mechanism fails to properly normalize these paths, potentially allowing attackers to traverse file system boundaries. This canonicalization failure occurs during the parsing and rendering of RSS content, where relative paths and URL components are not correctly resolved against the intended base URL. The improper handling creates opportunities for attackers to construct malicious RSS feed entries that, when processed by Safari, could result in unintended file system access. This type of vulnerability falls under the CWE-22 category for Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal.
The operational impact of CVE-2011-0244 extends beyond simple information disclosure, as it could enable attackers to access arbitrary files on the victim's system. This capability could potentially lead to the exposure of sensitive user data, system configuration files, or even credentials stored in accessible locations. The user-assisted nature of the attack means that victims must actively interact with the malicious RSS feed content, typically by viewing it within Safari's RSS reader or by visiting a webpage that displays the compromised feed. This requirement for user interaction reduces the automatic exploitation potential but still represents a significant security risk in environments where users frequently consume RSS feeds from untrusted sources. The vulnerability affects a broad user base given Safari's widespread adoption on macOS and iOS platforms, making it particularly concerning for enterprise and personal security.
Mitigation strategies for this vulnerability primarily focus on immediate software updates to the affected Safari versions, with Apple releasing patches in Safari 5.0.6 and subsequent releases. Organizations should implement comprehensive patch management processes to ensure timely deployment of security updates across all affected systems. Additionally, network administrators can consider implementing web filtering solutions that block access to potentially malicious RSS feeds or content from untrusted sources. Browser security configurations should be reviewed to limit the execution of potentially dangerous content, and users should be educated about the risks of consuming RSS feeds from unknown or untrusted sources. The vulnerability highlights the importance of proper input validation and URL canonicalization in web applications, particularly in browser environments where content from multiple sources is processed and rendered. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and information gathering through improper input handling, emphasizing the need for robust security controls in web browser implementations.