CVE-2012-3747 in iOS
Summary
by MITRE
WebKit, as used in Apple iOS before 6, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.
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Analysis
by VulDB Data Team • 04/14/2021
The vulnerability identified as CVE-2012-3747 represents a critical memory corruption flaw within WebKit, the web rendering engine that powers Apple iOS browsers and embedded web views. This vulnerability specifically affected Apple iOS versions prior to iOS 6, creating a significant security risk that could be exploited by remote attackers through maliciously crafted websites. The flaw resides in how WebKit processes certain web content, leading to unpredictable memory behavior that adversaries could manipulate to gain unauthorized system access or disrupt normal application functionality.
The technical nature of this vulnerability stems from improper memory handling within WebKit's JavaScript engine and rendering components. When processing specially crafted web pages containing malformed JavaScript or HTML elements, the engine fails to properly validate memory allocations and deallocations, resulting in memory corruption that can be leveraged to execute arbitrary code. This type of vulnerability falls under the CWE-125 vulnerability class, which encompasses out-of-bounds read conditions that can lead to memory corruption and potential code execution. The flaw demonstrates characteristics consistent with heap-based buffer overflows and use-after-free conditions that are commonly exploited in browser-based attacks.
From an operational perspective, this vulnerability created severe security implications for iOS users, as it allowed remote code execution without requiring any user interaction beyond visiting a malicious website. The attack vector was particularly dangerous because it could be delivered through standard web browsing activities, making it difficult for users to protect themselves. The potential impact included complete system compromise, data theft, persistent backdoor installation, and denial of service scenarios that could render devices unusable. Security researchers noted that the vulnerability could be exploited through various attack chains, including JavaScript-based exploits that took advantage of the browser's memory management flaws to escalate privileges and execute malicious payloads.
The exploitation of CVE-2012-3747 aligns with tactics documented in the MITRE ATT&CK framework under the T1059.007 technique for JavaScript execution and T1068 for local privilege escalation. Organizations and users were advised to implement immediate mitigation strategies including prompt OS updates to iOS 6 or later versions, which contained patches addressing the underlying memory corruption issues. Additional protective measures included implementing network-level filtering to block suspicious content, using secure browsing practices, and maintaining up-to-date security software. The vulnerability highlighted the importance of regular security updates and demonstrated how browser-based exploits could bypass traditional network security controls. This incident reinforced the critical need for continuous vulnerability management and the implementation of defense-in-depth strategies to protect against sophisticated browser-based attacks that leverage memory corruption flaws in widely-used software components.