CVE-2009-2206 in iPhone OS
Summary
by MITRE
Multiple heap-based buffer overflows in the AudioCodecs library in the CoreAudio component in Apple iPhone OS before 3.1, and iPhone OS before 3.1.1 for iPod touch, allow remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted (1) AAC or (2) MP3 file, as demonstrated by a ringtone with malformed entries in the sample size table.
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Analysis
by VulDB Data Team • 06/15/2017
The vulnerability identified as CVE-2009-2206 represents a critical heap-based buffer overflow affecting Apple's CoreAudio component in iPhone OS versions prior to 3.1. This security flaw resides within the AudioCodecs library, which handles audio file processing for media playback including ringtones and audio content. The vulnerability specifically targets the parsing of Advanced Audio Coding and MPEG-1/2 Audio Layer III file formats, making it particularly dangerous given the widespread use of these audio codecs in mobile devices and user-generated content. The flaw enables remote attackers to execute arbitrary code or cause application crashes through manipulation of audio file structures, particularly when processing malformed sample size tables in ringtone files.
The technical implementation of this vulnerability stems from insufficient bounds checking within the CoreAudio library's audio codec processing routines. When the system attempts to parse malformed AAC or MP3 files, the AudioCodecs library fails to properly validate the size and structure of sample size tables within the audio file headers. This inadequate input validation leads to memory corruption as the system writes data beyond allocated buffer boundaries, creating opportunities for attackers to overwrite critical memory locations. The heap-based nature of the overflow indicates that the vulnerability occurs in dynamically allocated memory regions, making exploitation more complex but potentially more reliable than stack-based overflows. This flaw directly maps to CWE-121, Heap-based Buffer Overflow, which describes buffer overflows occurring in heap memory allocated at runtime.
The operational impact of CVE-2009-2206 extends beyond simple denial of service scenarios to enable full remote code execution capabilities. Attackers can craft malicious audio files that, when processed by the iPhone's media system, trigger the buffer overflow and potentially allow arbitrary code execution with the privileges of the affected application. This represents a significant threat to mobile device security as it allows attackers to compromise user devices through seemingly benign audio content such as ringtones or music files. The vulnerability particularly affects the iPhone's ringtone functionality, which processes user-defined audio content, making it possible for attackers to deliver malicious payloads through social engineering or compromised content distribution channels. The impact is further amplified by the fact that these vulnerabilities exist in the core audio processing components that handle media playback across the entire operating system.
Mitigation strategies for this vulnerability require immediate system updates to iPhone OS 3.1 or later versions, which contain patches addressing the buffer overflow conditions in the AudioCodecs library. System administrators and users should implement comprehensive patch management procedures to ensure all affected devices receive the necessary security updates. Additional protective measures include implementing network-based filtering to block suspicious audio file content, disabling automatic ringtone installation from untrusted sources, and maintaining updated antivirus solutions that can detect and prevent exploitation attempts. The vulnerability demonstrates the importance of secure coding practices in mobile operating systems, particularly in components that process user-supplied content, aligning with ATT&CK technique T1068 which covers exploit for privilege escalation. Organizations should also consider implementing network segmentation and monitoring to detect potential exploitation attempts, as the vulnerability can be leveraged for more sophisticated attacks including persistent backdoor installation.