CVE-2008-3632 in iPod touch
Summary
by MITRE
Use-after-free vulnerability in WebKit in Apple iPod touch 1.1 through 2.0.2, and iPhone 1.0 through 2.0.2, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a web page with crafted Cascading Style Sheets (CSS) import statements.
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Analysis
by VulDB Data Team • 04/13/2025
This vulnerability represents a critical use-after-free flaw within the WebKit rendering engine that powers Apple's mobile browsers in iPod touch and iPhone devices. The issue specifically manifests when processing crafted CSS import statements that trigger memory management errors during the rendering process. The vulnerability affects a broad range of iOS versions from iPod touch 1.1 through 2.0.2 and iPhone 1.0 through 2.0.2, indicating it was present in the core web rendering infrastructure for several generations of mobile devices. The flaw stems from improper memory deallocation and subsequent reuse of memory blocks that contain CSS processing objects, creating opportunities for attackers to manipulate the memory layout and execute arbitrary code or force application crashes.
The technical implementation of this vulnerability involves the WebKit engine's handling of CSS import directives where the memory allocated for CSS objects is freed before all references to that memory are properly dereferenced. When a malicious web page contains carefully crafted CSS import statements, the engine's parser processes these directives in a way that leads to a race condition or improper memory management sequence. This particular weakness maps directly to CWE-416, which describes the use of freed memory vulnerability, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The vulnerability demonstrates how CSS processing can be weaponized to exploit fundamental memory management flaws in web rendering engines, making it particularly dangerous as it can be triggered through standard web browsing activities.
The operational impact of this vulnerability extends beyond simple denial of service to include full remote code execution capabilities, making it a severe threat to mobile device security. Attackers can craft malicious web pages that, when loaded in the affected browsers, will cause the application to crash or potentially execute malicious code with the privileges of the browser process. This creates a significant risk for users who browse untrusted websites, as the exploit can be delivered through standard web traffic without requiring any special user interaction beyond visiting a malicious site. The vulnerability affects not just individual users but also enterprise environments where mobile device security is paramount, as compromised devices can serve as entry points for broader network attacks.
Mitigation strategies for this vulnerability require immediate patching of affected iOS versions through official Apple updates, as the flaw existed in multiple generations of mobile operating systems. Organizations should implement network-level protections such as web filtering and content validation to prevent access to known malicious sites, while also monitoring for exploitation attempts. The fix typically involves memory management improvements in WebKit's CSS processing routines, ensuring proper reference counting and memory deallocation sequences. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their mobile devices updated with the latest security patches. Security teams should also consider implementing browser sandboxing measures and monitoring for unusual application crashes or memory access patterns that might indicate exploitation attempts, aligning with ATT&CK techniques for defensive measures against remote code execution vulnerabilities.