CVE-2011-0157 in iOS
Summary
by MITRE
WebKit, as used in Apple iOS before 4.3, 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 CVEs listed in APPLE-SA-2011-03-09-1.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/16/2017
The vulnerability identified as CVE-2011-0157 represents a critical memory corruption flaw within WebKit engine implementation in Apple iOS versions prior to 4.3. This vulnerability exists within the browser rendering engine that powers Safari and other web-based applications on iOS devices, creating a pathway for remote code execution through maliciously crafted web content. The flaw specifically affects how WebKit processes certain web page elements, leading to unpredictable behavior that can be exploited by attackers to gain unauthorized control over affected devices. This vulnerability demonstrates the inherent risks associated with complex web rendering engines that must process untrusted content from multiple sources while maintaining memory safety and application stability.
The technical nature of this vulnerability stems from improper memory management within WebKit's JavaScript engine and rendering components. Attackers can craft specific web pages containing malicious code that triggers buffer overflows, use-after-free conditions, or other memory corruption patterns when the browser attempts to render the content. These memory corruption issues typically occur during the processing of complex web elements such as JavaScript objects, DOM manipulation operations, or graphics rendering commands. The vulnerability's exploitation mechanism aligns with common software security weaknesses classified under CWE-125, which deals with out-of-bounds read conditions, and CWE-787, which addresses out-of-bounds write conditions. The flaw enables attackers to manipulate memory layout and potentially overwrite critical program structures, leading to arbitrary code execution or application crashes that can be leveraged for more sophisticated attacks.
The operational impact of CVE-2011-0157 extends beyond simple denial of service scenarios to encompass full system compromise potential. When exploited, this vulnerability allows remote attackers to execute arbitrary code with the privileges of the affected application, typically resulting in complete device control. Users visiting malicious websites could unknowingly trigger the exploit, making this a particularly dangerous vulnerability for mobile environments where users frequently browse untrusted web content. The vulnerability's presence in iOS versions before 4.3 meant that millions of devices were potentially exposed to attacks, as iOS devices were commonly used for sensitive data access and communication. The attack surface is broad due to WebKit's integration across multiple iOS applications and services, including Safari, Mail, and various built-in web-based features that rely on the same rendering engine.
Mitigation strategies for this vulnerability require immediate system updates and security hardening measures. The primary and most effective solution involves upgrading to iOS 4.3 or later versions where Apple has implemented memory safety improvements and code validation mechanisms. Security professionals should implement network-based protections such as web application firewalls and content filtering systems that can detect and block known exploit patterns. Additionally, users should maintain awareness of phishing attempts and avoid visiting untrusted websites, particularly those containing suspicious JavaScript or multimedia content. The vulnerability's characteristics align with ATT&CK technique T1203, which covers exploitation for execution through web-based attacks, making defensive measures such as browser sandboxing and privilege separation particularly relevant. Organizations should also consider implementing mobile device management solutions that can enforce security policies and ensure timely patch deployment across enterprise iOS devices.