CVE-2018-9573 in Android
Summary
by MITRE
In impd_parse_filt_block of impd_drc_dynamic_payload.c there is a possible out of bounds write due to 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-116467350.
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Analysis
by VulDB Data Team • 04/19/2020
The vulnerability identified as CVE-2018-9573 resides within the Android operating system's audio processing subsystem, specifically in the impd_drc_dynamic_payload.c source file. This issue manifests as a potential out of bounds write condition that occurs during the parsing of dynamic range compression filter blocks. The flaw is particularly concerning because it exists in the impd_parse_filt_block function where proper bounds checking mechanisms are absent, allowing maliciously crafted audio data to potentially overwrite memory regions beyond the intended buffer boundaries. The vulnerability affects Android 9.0 releases and represents a critical security weakness that could be exploited to achieve remote code execution without requiring any additional privileges or user interaction beyond the initial exploitation vector.
The technical implementation of this vulnerability stems from insufficient input validation within the dynamic range compression processing logic. When the system processes audio data containing specially crafted dynamic range compression parameters, the parsing function fails to verify that the incoming data fits within allocated memory buffers. This missing bounds check creates an exploitable condition where an attacker can manipulate the filter block parameters to cause memory corruption, potentially leading to arbitrary code execution. The vulnerability's classification as a remote code execution issue indicates that it can be triggered through network-based attacks, making it particularly dangerous in mobile environments where users frequently interact with external audio content.
The operational impact of CVE-2018-9573 extends beyond simple memory corruption, as it represents a serious threat to Android device security and user privacy. The vulnerability's ability to enable remote code execution without additional privileges means that attackers could potentially gain full control over affected devices. This capability is particularly concerning given that audio processing occurs frequently in mobile environments, making exploitation more likely through various attack vectors such as malicious media files, network streams, or compromised applications that process audio content. The requirement for user interaction suggests that social engineering attacks might be necessary to deliver the malicious payload, but once triggered, the vulnerability provides a powerful exploitation primitive for attackers.
Mitigation strategies for this vulnerability should focus on implementing proper bounds checking mechanisms within the audio processing pipeline and ensuring that all input data is validated before processing. The recommended approach includes applying the latest Android security patches and updates from Google, which contain the necessary code modifications to address the missing bounds checks. Additionally, system administrators should consider implementing network-level protections such as content filtering and sandboxing mechanisms to limit the potential impact of exploitation attempts. From a defensive perspective, this vulnerability aligns with CWE-129, which describes improper validation of array indices, and may be categorized under ATT&CK technique T1059 for remote code execution through system processes. The fix typically involves adding proper input validation and bounds checking before any memory writes occur during audio data processing, ensuring that all dynamic range compression parameters are properly validated against expected ranges and buffer sizes.