CVE-2011-0235 in Safari
Summary
by MITRE
WebKit, as used in Apple Safari before 5.0.6, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulnerability than other WebKit CVEs listed in APPLE-SA-2011-07-20-1.
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Analysis
by VulDB Data Team • 11/15/2021
The vulnerability identified as CVE-2011-0235 represents a critical memory corruption flaw within WebKit engine's JavaScriptCore component that affected Apple Safari versions prior to 5.0.6. This vulnerability demonstrates the inherent complexity and risk associated with modern web browsers that must execute untrusted code from multiple sources while maintaining robust security boundaries. The flaw exists in the JavaScript engine's handling of certain memory operations during web page rendering, creating a pathway for malicious actors to exploit the browser's memory management systems.
The technical implementation of this vulnerability involves a specific memory corruption issue that occurs when WebKit processes malformed JavaScript code or HTML elements within web pages. Attackers can craft malicious websites that trigger buffer overflows or use-after-free conditions within the JavaScriptCore engine, which is responsible for executing JavaScript code in Safari. This particular flaw operates at the intersection of memory management and code execution, allowing remote attackers to manipulate memory pointers and potentially overwrite critical system structures. The vulnerability's classification aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations that can lead to memory corruption.
The operational impact of this vulnerability extends beyond simple code execution to include potential system compromise and denial of service scenarios. When successfully exploited, the vulnerability can cause Safari to crash or behave unpredictably, potentially allowing attackers to execute arbitrary code with the privileges of the user running the browser. This represents a significant threat to user security as it enables attackers to bypass traditional security boundaries and potentially gain access to sensitive user data, cookies, or other browser-stored information. The vulnerability's impact is particularly concerning given Safari's widespread use among Mac users and its integration with other Apple services that may be compromised through browser exploitation.
Mitigation strategies for CVE-2011-0235 focus primarily on immediate patching and system updates as recommended by Apple's security advisory. Users should upgrade to Safari 5.0.6 or later versions that contain the necessary memory management fixes and code validation improvements. Additionally, browser hardening techniques including sandboxing mechanisms, address space layout randomization, and strict memory access controls should be implemented to reduce the attack surface. Security professionals should also consider implementing network-based protections such as web application firewalls that can detect and block suspicious JavaScript patterns. The vulnerability's characteristics make it particularly susceptible to defense-in-depth approaches, where multiple security layers work together to prevent exploitation. Organizations should also maintain awareness of related vulnerabilities in the WebKit ecosystem and ensure comprehensive patch management processes are in place to address similar memory corruption issues that may arise from the complex interaction between JavaScript engines and web rendering components.