CVE-2018-9479 in Android
Summary
by MITRE • 11/20/2024
In process_service_attr_req and process_service_search_attr_req of sdp_server.cc, there is an 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 not needed for exploitation.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9479 represents a critical out-of-bounds write flaw within the Bluetooth Service Discovery Protocol (SDP) server implementation of the BlueZ stack. This security weakness exists in the process_service_attr_req and process_service_search_attr_req functions located in the sdp_server.cc source file, where inadequate bounds checking allows attackers to manipulate memory regions beyond their intended boundaries. The flaw specifically affects the handling of service attribute requests and service search attribute requests within the Bluetooth protocol stack, creating a pathway for malicious actors to exploit the system's memory management mechanisms. The vulnerability's severity is amplified by its remote exploitability, meaning that an attacker can trigger the flaw without requiring physical access or user interaction, making it particularly dangerous in networked environments where Bluetooth devices are prevalent.
The technical exploitation of this vulnerability stems from improper validation of input data structures during SDP request processing. When the Bluetooth service discovery protocol server receives malformed attribute or search attribute requests, it fails to verify that the incoming data fits within allocated memory buffers before writing to memory locations. This missing bounds check creates a classic buffer overflow condition that can be leveraged to overwrite adjacent memory locations, potentially including return addresses, function pointers, or other critical program state information. The absence of user interaction requirements means that exploitation can occur automatically when vulnerable Bluetooth services are active, making this vulnerability particularly concerning for mobile devices, IoT systems, and any networked equipment that utilizes Bluetooth connectivity. The flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a significant weakness in the memory safety mechanisms of the Bluetooth protocol implementation.
The operational impact of CVE-2018-9479 extends beyond simple system instability, as the vulnerability can be weaponized to achieve remote code execution without requiring elevated privileges or user interaction. Attackers can craft specially malformed SDP requests that, when processed by vulnerable systems, trigger the out-of-bounds write condition and potentially allow arbitrary code execution within the context of the Bluetooth service process. This capability enables threat actors to gain persistent access to affected devices, potentially leading to complete system compromise, data exfiltration, or the establishment of backdoors. The vulnerability affects a wide range of devices that implement the BlueZ Bluetooth stack, including smartphones, tablets, laptops, embedded systems, and IoT devices that rely on Bluetooth for service discovery operations. The remote nature of the exploit means that attackers can target vulnerable systems from anywhere within Bluetooth range, making this vulnerability particularly dangerous in public spaces or enterprise environments where Bluetooth services are actively exposed.
Mitigation strategies for CVE-2018-9479 should focus on immediate patching of affected BlueZ implementations, as the vulnerability requires no special privileges for exploitation and can be triggered remotely. Organizations should prioritize updating their Bluetooth stack implementations to versions that include proper bounds checking in the SDP server processing functions, ensuring that input validation occurs before memory writes are performed. Network administrators should consider disabling unnecessary Bluetooth services when not actively required, particularly in enterprise environments where Bluetooth exposure increases attack surface. Additional protective measures include implementing network segmentation to limit Bluetooth connectivity, deploying intrusion detection systems that monitor for anomalous SDP traffic patterns, and conducting regular vulnerability assessments to identify potentially affected systems. The ATT&CK framework categorizes this vulnerability under T1059.007 for remote code execution techniques, and organizations should consider implementing defensive measures against such attack vectors. System administrators should also monitor for unusual Bluetooth service activity and implement proper access controls to limit exposure of vulnerable Bluetooth services to untrusted networks or users.