CVE-2011-0240 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.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2011-0240 represents a critical memory corruption flaw within WebKit's JavaScript engine that affected Apple Safari versions prior to 5.0.6. This vulnerability operates through a sophisticated attack vector that leverages crafted web content to exploit memory management issues within the browser's rendering engine. The flaw specifically targets the JavaScriptCore component of WebKit, which handles JavaScript execution and memory allocation for web page scripting. Attackers can construct malicious web pages that, when loaded in affected Safari browsers, trigger unpredictable memory behavior leading to arbitrary code execution or system crashes. The vulnerability demonstrates characteristics consistent with heap-based buffer overflow conditions where improper memory handling allows attackers to manipulate memory layout and execute malicious payloads. This issue falls under the broader category of memory safety vulnerabilities that have historically represented some of the most dangerous classes of flaws in web browsers due to their potential for remote code execution.
The technical implementation of this vulnerability involves exploiting weaknesses in how WebKit's JavaScript engine manages object allocation and memory deallocation during script execution. When a malicious web page is rendered, specific JavaScript code patterns can trigger memory corruption conditions that cause the browser to write beyond allocated memory boundaries or execute corrupted memory regions. The flaw typically manifests through improper handling of object references, array bounds checking failures, or memory deallocation sequences that leave memory in an inconsistent state. Attackers can craft JavaScript code that, when executed, causes the browser to allocate memory in predictable patterns, then corrupts that memory through controlled inputs that bypass normal safety checks. This allows for the execution of arbitrary code with the privileges of the browser process, potentially leading to complete system compromise. The vulnerability's classification aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are fundamental memory safety issues.
The operational impact of CVE-2011-0240 extends beyond simple denial of service scenarios to represent a significant threat to user security and system integrity. When exploited, this vulnerability allows attackers to gain remote code execution capabilities, potentially enabling them to install malware, steal user credentials, or access sensitive data stored on the compromised system. The attack surface is particularly concerning because it leverages the browser as an attack vector, which users frequently interact with during normal browsing activities. The vulnerability's exploitation requires no local privileges or user interaction beyond visiting a malicious website, making it highly dangerous in real-world scenarios. Security researchers have documented cases where this vulnerability was actively exploited in the wild, demonstrating its practical threat level to organizations and individual users. The impact is amplified by the widespread adoption of Safari as a primary browser on macOS systems, creating a large potential attack surface for threat actors targeting Apple users.
Mitigation strategies for CVE-2011-0240 focus primarily on updating to patched versions of Apple Safari, specifically version 5.0.6 or later, which contain memory safety improvements and code fixes addressing the underlying JavaScript engine flaws. System administrators should implement comprehensive patch management procedures to ensure all affected Safari installations are updated promptly. Browser vendors recommend enabling automatic updates where possible, as this vulnerability was actively exploited in the wild. Additional protective measures include implementing browser security features such as sandboxing, which limits the damage that can occur if a vulnerability is successfully exploited. Organizations should also consider deploying web application firewalls and content filtering solutions that can detect and block known malicious patterns associated with this vulnerability. From an operational security perspective, users should be educated about the risks of visiting untrusted websites and the importance of keeping their browsers updated. The vulnerability's resolution demonstrates the importance of regular security updates and the critical role that browser vendors play in maintaining secure web environments, aligning with ATT&CK technique T1211 which covers exploitation for defense evasion and T1059 which covers command and scripting interpreter usage in exploitation scenarios.