CVE-2018-9541 in Android
Summary
by MITRE
In avrc_pars_vendor_rsp of avcr_pars_ct.cc, there is a possible out-of-bounds read due to a missing bounds check. This could lead to remote information disclosure in the Bluetooth service 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. Android ID: A-111450531
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Analysis
by VulDB Data Team • 04/13/2020
The vulnerability identified as CVE-2018-9541 represents a critical out-of-bounds read flaw within the Bluetooth AVRCP (Audio Video Remote Control Profile) implementation of Android operating systems. This issue exists in the avrc_pars_vendor_rsp function located in the avcr_pars_ct.cc source file, where a fundamental bounds checking mechanism has been omitted during the parsing of vendor-specific responses. The flaw specifically affects Android versions ranging from 7.0 through 9.0, encompassing a significant portion of the mobile platform ecosystem that relies heavily on Bluetooth connectivity for various audio and media control functions.
The technical nature of this vulnerability stems from insufficient input validation during the parsing of Bluetooth vendor response packets, which allows an attacker to craft malicious Bluetooth packets that trigger memory access violations. When the Bluetooth service processes these malformed vendor responses without proper bounds checking, it attempts to read memory beyond the allocated buffer boundaries, potentially exposing sensitive information from adjacent memory locations. This type of vulnerability falls under CWE-129, which specifically addresses insufficient bounds checking, and represents a classic example of how improper input validation can lead to information disclosure vulnerabilities. The flaw's classification as a remote information disclosure means that an attacker can exploit this vulnerability without requiring physical access or additional privileges beyond what is already available through Bluetooth connectivity.
The operational impact of CVE-2018-9541 extends beyond simple information disclosure, as it can potentially reveal sensitive system information, memory contents, or configuration data that could aid in further exploitation attempts. The vulnerability's remote exploitability without user interaction makes it particularly dangerous in mobile environments where Bluetooth is constantly active and frequently paired with various devices. Attackers could leverage this flaw to gather information about the target device's memory layout, system configuration, or potentially even credentials stored in adjacent memory regions. This vulnerability directly aligns with ATT&CK technique T1059.001, which covers command and script injection, as the information disclosure could enable more sophisticated attacks. The lack of user interaction requirements means that the exploit can be delivered passively, making it especially concerning for mobile platforms where users frequently connect to unknown Bluetooth devices in public spaces.
Mitigation strategies for CVE-2018-9541 should prioritize the immediate deployment of Android security patches provided by Google, which include the necessary bounds checking modifications to prevent the out-of-bounds read condition. System administrators and device manufacturers should implement comprehensive Bluetooth security policies that limit exposure windows and disable unnecessary Bluetooth services when not actively in use. Network segmentation and monitoring solutions should be deployed to detect anomalous Bluetooth traffic patterns that might indicate exploitation attempts. Additionally, organizations should conduct regular security assessments of their mobile device management policies to ensure that all Android devices within their environment receive timely security updates. The vulnerability highlights the importance of proper input validation in network protocol implementations and serves as a reminder that even seemingly benign Bluetooth services can become attack vectors when proper security controls are not implemented. Security teams should also consider implementing Bluetooth traffic monitoring to detect potential exploitation attempts and maintain detailed logs of Bluetooth connectivity events for forensic analysis purposes.