CVE-2012-3640 in iOS
Summary
by MITRE
WebKit, as used in Apple Safari before 6.0, 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-2012-07-25-1.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability identified as CVE-2012-3640 represents a critical memory corruption flaw within WebKit engine components that powered Apple Safari browsers prior to version 6.0. This issue stems from improper handling of memory structures during web page rendering processes, creating a pathway for malicious actors to exploit the browser's memory management system. The vulnerability specifically affects the JavaScriptCore engine component within WebKit, which is responsible for executing JavaScript code in web applications. Attackers can craft malicious web pages that trigger memory corruption when the browser attempts to process certain JavaScript constructs or DOM manipulations, leading to unpredictable behavior in the application's memory space.
The technical exploitation of this vulnerability occurs through carefully constructed web content that leverages memory corruption patterns within the WebKit rendering engine. When Safari processes these malicious web pages, the JavaScriptCore engine fails to properly validate memory access patterns, allowing attackers to overwrite critical memory locations or execute arbitrary code within the browser's process space. This memory corruption can manifest as either arbitrary code execution capabilities or denial of service conditions that cause the browser to crash and terminate unexpectedly. The vulnerability's impact extends beyond simple exploitation as it can be triggered through ordinary web browsing activities, making it particularly dangerous for end users who may encounter malicious content without direct interaction with known attack vectors.
From an operational perspective, this vulnerability poses significant risks to enterprise and individual users who rely on Safari for web browsing activities. The ability to execute arbitrary code remotely means that attackers can potentially gain full control of affected systems, install malware, steal sensitive data, or establish persistent access points. The vulnerability's classification as a memory corruption issue aligns with CWE-125, which describes out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution. Additionally, this vulnerability demonstrates characteristics consistent with ATT&CK technique T1059.007, which involves the use of scripting languages for execution, as attackers can leverage JavaScript to exploit the underlying memory management flaws.
The attack surface for this vulnerability encompasses any user of Safari versions prior to 6.0 who visits malicious websites or encounters compromised web content. The exploitation requires no special privileges or user interaction beyond normal web browsing, making it particularly dangerous as a zero-day exploit. Organizations should consider implementing network-level protections such as web application firewalls and content filtering solutions to mitigate exposure while awaiting patches. The vulnerability also highlights the importance of regular software updates and the risks associated with outdated browser versions, as the issue was resolved through Apple's security updates released in July 2012. Security professionals should note that this vulnerability represents a classic example of how browser engine vulnerabilities can provide attackers with powerful exploitation capabilities, emphasizing the need for continuous monitoring and rapid response to emerging threats in web browser environments.