CVE-2018-9532 in Android
Summary
by MITRE
In ixheaacd_extract_frame_info_ld of ixheaacd_env_extr.c there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation. Product: Android. Versions: Android-9. Android ID: A-112765917
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Analysis
by VulDB Data Team • 04/13/2020
The vulnerability identified as CVE-2018-9532 represents a critical out-of-bounds write flaw within the Android media processing pipeline, specifically affecting the ixheaacd_extract_frame_info_ld function in the ixheaacd_env_extr.c source file. This issue resides within the audio decoding component of the Android operating system, which processes compressed audio streams using the ixheaacd codec. The vulnerability stems from an insufficient bounds checking mechanism that fails to validate input data boundaries before writing to memory locations, creating a potential avenue for malicious code injection. The flaw manifests when the decoder encounters malformed audio data that triggers an improper memory access pattern, allowing an attacker to write data beyond the allocated buffer boundaries. This particular vulnerability affects Android 9.0 and represents a significant security risk as it enables remote code execution without requiring elevated privileges or user interaction beyond initial exploitation. The vulnerability's classification under CWE-787 indicates a direct out-of-bounds write condition where memory is accessed beyond the bounds of a buffer, which is a well-documented and dangerous class of vulnerabilities. The attack vector for this vulnerability is particularly concerning as it can be exploited remotely through maliciously crafted audio files or streams, making it a prime target for attackers seeking to compromise Android devices without physical access or user consent. The requirement for user interaction suggests that exploitation typically occurs when a user opens or plays a specially crafted audio file, making it a social engineering component in the attack chain. The Android ID A-112765917 specifically identifies this vulnerability within Google's internal tracking system, indicating its recognition and prioritization within the Android security framework. This vulnerability operates at a low-level within the audio processing stack, making it particularly dangerous as it can potentially bypass standard security mechanisms that operate at higher levels of the system architecture. The impact of this vulnerability extends beyond simple code execution, as it can potentially allow attackers to gain unauthorized access to device resources, modify system behavior, or establish persistent access points within the Android environment. The missing bounds check in the ixheaacd_extract_frame_info_ld function creates a scenario where attacker-controlled data can manipulate memory layout, potentially leading to arbitrary code execution. This type of vulnerability aligns with ATT&CK technique T1059.007 which covers the use of scripting languages for code execution, as the out-of-bounds write could enable attackers to inject and execute malicious payloads within the audio processing context. The vulnerability's remote execution capability makes it particularly attractive to threat actors targeting mobile devices, as it can be exploited through various attack vectors including email attachments, web downloads, or malicious applications. The lack of privilege escalation requirements means that successful exploitation can result in full device compromise without the need for additional attack vectors or user permissions. The vulnerability's presence in the Android 9.0 release cycle indicates that it was present in a significant number of devices, potentially exposing millions of users to remote code execution risks. Security researchers have noted that such buffer overflow vulnerabilities in media processing components often require careful analysis of the input parsing logic and memory management patterns to fully understand the exploitation potential and develop appropriate mitigations. The fix for this vulnerability would typically involve implementing proper bounds checking mechanisms, ensuring that all input data is validated before memory operations occur, and potentially adding additional input sanitization steps to prevent malformed data from triggering the out-of-bounds write condition. The vulnerability serves as a reminder of the critical importance of memory safety in system components, particularly those handling user-provided data streams in mobile operating systems where device security is paramount to user privacy and data protection.