CVE-2018-9504 in Android
Summary
by MITRE
In sdp_copy_raw_data of sdp_discovery.cc, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote code execution over bluetooth with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android Versions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9.0 Android ID: A-110216176
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Analysis
by VulDB Data Team • 03/29/2020
The vulnerability identified as CVE-2018-9504 represents a critical out-of-bounds write flaw within the Bluetooth service discovery protocol implementation in Android operating systems. This issue exists in the sdp_copy_raw_data function located in sdp_discovery.cc, where an incorrect bounds check allows malicious data to be written beyond the allocated memory buffer. The vulnerability affects multiple Android versions including 7.0, 7.1.1, 7.1.2, 8.0, 8.1, and 9.0, making it a widespread concern across the Android ecosystem. The flaw specifically resides in the Bluetooth Service Discovery Protocol (SDP) handling mechanism which is responsible for discovering and retrieving information about Bluetooth services available on nearby devices.
The technical nature of this vulnerability stems from improper validation of data length during Bluetooth service discovery operations. When processing incoming Bluetooth SDP records, the sdp_copy_raw_data function fails to properly verify that the source data length does not exceed the destination buffer capacity before performing the copy operation. This incorrect bounds checking creates a scenario where an attacker can craft malicious Bluetooth SDP data packets that, when processed by the vulnerable Android device, trigger memory corruption. The flaw allows for arbitrary memory writes beyond the intended buffer boundaries, potentially enabling attackers to overwrite adjacent memory locations with controlled data. This type of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation in network protocol handling.
The operational impact of CVE-2018-9504 is particularly severe as it enables remote code execution without requiring any user interaction or additional privileges. This means that an attacker positioned within Bluetooth range of a vulnerable Android device can exploit this vulnerability simply by advertising malicious Bluetooth services or initiating a connection with specially crafted SDP records. The attack vector operates entirely over the Bluetooth protocol without needing physical access to the device or any form of user engagement, making it highly dangerous in environments where Bluetooth connectivity is common. The vulnerability essentially provides a direct pathway for attackers to execute arbitrary code on target devices, potentially leading to complete system compromise, data exfiltration, or further lateral movement within networked environments.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1041, which covers data compression and encryption techniques used in command and control communications, as the Bluetooth protocol can be leveraged for covert attack delivery. The lack of user interaction requirement places this vulnerability in the category of zero-click exploits, making it particularly concerning for mobile device security. Organizations and users should consider implementing network segmentation strategies to limit Bluetooth connectivity in sensitive environments, while also prioritizing immediate patch deployment for affected Android versions. The vulnerability demonstrates the critical importance of robust input validation in network protocol implementations and highlights the risks associated with Bluetooth service discovery mechanisms in mobile operating systems. Security teams should monitor for potential exploitation attempts through Bluetooth network traffic analysis and implement proper device firmware updates to mitigate this risk across all affected Android platforms.