CVE-2020-9954 in iOS
Summary
by MITRE • 12/09/2020
A buffer overflow issue was addressed with improved memory handling. This issue is fixed in watchOS 7.0, tvOS 14.0, macOS Catalina 10.15.7, Security Update 2020-005 High Sierra, Security Update 2020-005 Mojave, iOS 14.0 and iPadOS 14.0. Playing a malicious audio file may lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 12/14/2020
The vulnerability identified as CVE-2020-9954 represents a critical buffer overflow flaw that was discovered in Apple's operating systems, specifically affecting iOS, iPadOS, macOS, watchOS, and tvOS platforms. This issue stems from inadequate memory handling mechanisms within the audio processing components of these systems, creating a potential pathway for attackers to execute arbitrary code through maliciously crafted audio files. The vulnerability is classified under CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw manifests when the system processes audio files that contain specially crafted data structures designed to exceed allocated buffer boundaries, potentially allowing attackers to manipulate program execution flow.
The technical implementation of this vulnerability involves improper input validation within the audio decoding subsystem where the application fails to properly verify the size and structure of incoming audio data before attempting to store it in fixed-size memory buffers. This memory handling deficiency creates a scenario where an attacker can construct an audio file with oversized or malformed data segments that, when played through the affected system, trigger the buffer overflow condition. The overflow can overwrite critical memory locations including return addresses, function pointers, or other control data structures, enabling attackers to redirect program execution to malicious code payloads. The exploit requires no special privileges or user interaction beyond playing the malicious file, making it particularly dangerous as it can be delivered through various attack vectors including email attachments, malicious websites, or compromised media files.
The operational impact of CVE-2020-9954 extends beyond simple code execution capabilities to encompass potential system compromise and data theft scenarios. Attackers leveraging this vulnerability could gain full control over affected devices, potentially accessing sensitive user data, intercepting communications, or establishing persistent backdoors for further exploitation. The widespread nature of the affected platforms means that users across multiple Apple ecosystems could be at risk, from mobile devices to desktop computers and wearable technology. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as it provides the initial foothold for more sophisticated attacks. The security implications also extend to enterprise environments where the vulnerability could be exploited to target high-value corporate devices, potentially compromising entire network infrastructures through device-based attacks.
Apple addressed this vulnerability through comprehensive memory management improvements in their security updates, including enhanced bounds checking, improved input validation, and stricter buffer allocation mechanisms. The remediation efforts covered all affected operating systems including watchOS 7.0, tvOS 14.0, macOS Catalina 10.15.7, and the respective security updates for High Sierra and Mojave. Organizations should prioritize immediate deployment of these patches across all affected systems and implement additional monitoring for suspicious audio file handling activities. The vulnerability serves as a reminder of the critical importance of robust memory safety practices in multimedia processing components and highlights the need for continuous security assessments of system libraries and frameworks. Network administrators should consider implementing content filtering measures to prevent the delivery of potentially malicious audio files through corporate networks, while security teams should monitor for indicators of compromise related to this vulnerability in their threat intelligence feeds.