CVE-2015-5823 in iTunes
Summary
by MITRE
WebKit, as used in JavaScriptCore in Apple iOS before 9 and iTunes before 12.3, 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 WebKit CVEs listed in APPLE-SA-2015-09-16-1 and APPLE-SA-2015-09-16-3.
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Analysis
by VulDB Data Team • 11/22/2024
CVE-2015-5823 represents a critical memory corruption vulnerability within WebKit's JavaScriptCore engine that affected Apple iOS versions prior to 9 and iTunes versions prior to 12.3. This vulnerability resides in the JavaScriptCore JavaScript engine component of WebKit which serves as the core rendering and execution engine for web content in Apple's ecosystem. The flaw manifests when processing maliciously crafted web content that triggers undefined behavior in memory management operations, leading to potential arbitrary code execution or system instability.
The technical nature of this vulnerability stems from improper handling of memory allocation and deallocation within JavaScriptCore's garbage collection mechanisms. When a malicious website presents carefully constructed JavaScript code or web content, the engine fails to properly validate memory operations, creating conditions where memory can be overwritten or accessed in unauthorized ways. This type of vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations. The vulnerability is particularly dangerous because it operates at the intersection of JavaScript execution and low-level memory management, allowing attackers to exploit the boundary between interpreted JavaScript code and native memory operations.
From an operational perspective, this vulnerability presents a significant threat to Apple device users as it enables remote code execution through web browsing activities. Attackers can craft malicious websites that, when loaded in Safari or iTunes, trigger the memory corruption flaw and execute arbitrary code with the privileges of the affected application. This creates a persistent attack vector that can compromise user data, enable persistent backdoors, or facilitate further exploitation. The vulnerability's classification as a remote code execution flaw aligns with ATT&CK technique T1059.007, which covers JavaScript and VBScript execution, and T1203, which addresses exploitation for client execution through web-based attacks.
The impact extends beyond simple application crashes to encompass full system compromise potential, as successful exploitation could allow attackers to bypass security restrictions and access sensitive user information. This vulnerability represents a classic example of a heap-based buffer overflow or memory corruption issue that has been prevalent in JavaScript engines due to the complexity of managing dynamic memory allocation for interpreted languages. The fact that this vulnerability was separate from other WebKit CVEs indicates it involved distinct code paths or memory handling patterns within the JavaScriptCore implementation.
Mitigation strategies for CVE-2015-5823 primarily involve applying the official security updates released by Apple, which include patches to JavaScriptCore's memory management routines and enhanced input validation. Users should immediately update to iOS 9 or iTunes 12.3 and later versions to eliminate exposure to this vulnerability. Network-based defenses such as web application firewalls and content filtering systems can provide additional protection layers, though they cannot fully prevent exploitation of client-side vulnerabilities. Security monitoring should focus on detecting unusual JavaScript execution patterns and memory access anomalies that might indicate exploitation attempts. Organizations should also consider implementing browser hardening measures and restricting access to untrusted websites through corporate security policies. The vulnerability demonstrates the critical importance of maintaining up-to-date software patches and highlights the risks associated with running outdated operating systems and applications in enterprise environments.