CVE-2018-9456 in Android
Summary
by MITRE • 11/20/2024
In sdpu_extract_attr_seq of sdp_utils.cc, there is a possible out of bounds read due to an incorrect bounds check. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 02/24/2025
The vulnerability identified as CVE-2018-9456 represents a critical out-of-bounds read condition within the Bluetooth Service Discovery Protocol (SDP) implementation of the Android operating system. This flaw exists in the sdpu_extract_attr_seq function located in the sdp_utils.cc source file, which handles the parsing of SDP attribute sequences during Bluetooth service discovery operations. The vulnerability stems from an insufficient bounds checking mechanism that fails to properly validate the length of data being processed during attribute sequence extraction. This technical oversight creates a scenario where an attacker can craft malicious SDP packets that trigger memory access violations when the system attempts to parse malformed attribute sequences. The vulnerability is particularly concerning because it operates at the system level within Bluetooth protocol handling components, making it accessible to attackers who can potentially send crafted Bluetooth packets to target devices without requiring any special privileges or user interaction. The absence of user interaction requirements significantly increases the exploitability of this vulnerability, as it can be triggered automatically through network-based attacks or passive packet interception.
The operational impact of CVE-2018-9456 extends beyond simple denial of service to potentially compromise the stability and availability of Bluetooth services on affected Android devices. When exploited, this vulnerability can cause the Bluetooth subsystem to crash or hang, resulting in complete service disruption that prevents legitimate Bluetooth communications from functioning properly. The out-of-bounds read condition may also lead to memory corruption that could potentially be leveraged for more sophisticated attacks, though the current analysis indicates the primary risk remains denial of service. This vulnerability affects a wide range of Android versions and devices that implement the Bluetooth SDP protocol, making it particularly dangerous in environments where Bluetooth connectivity is essential for device functionality or security operations. The vulnerability's remote exploitation capability means that attackers can trigger the condition from outside the device's local network, potentially enabling large-scale disruption of Bluetooth services across multiple devices simultaneously.
Security mitigations for CVE-2018-9456 primarily focus on implementing proper bounds checking mechanisms within the SDP parsing routines to prevent out-of-bounds memory access. The recommended approach involves strengthening the validation logic in the sdpu_extract_attr_seq function to ensure that all attribute sequence lengths are properly verified before any memory operations are performed. This includes implementing comprehensive input validation that checks the integrity of SDP packet structures and validates the expected data lengths against actual available buffer space. System administrators and device manufacturers should prioritize applying the relevant security patches provided by Google and other vendors to address this vulnerability. Additionally, network monitoring solutions should be configured to detect and alert on anomalous Bluetooth SDP traffic patterns that may indicate exploitation attempts. From a defensive perspective, implementing network segmentation and access controls for Bluetooth services can help limit the potential impact of such vulnerabilities, while regular security assessments should include verification of Bluetooth protocol implementations to identify similar bounds checking issues. The vulnerability aligns with CWE-129, which describes improper validation of length of inputs to ensure they are within acceptable ranges, and represents a classic example of how insufficient input validation can lead to memory safety issues in network protocol implementations. This vulnerability also maps to ATT&CK technique T1059.007, which covers the use of remote services for command execution, as the vulnerability enables remote exploitation of Bluetooth services without requiring user interaction or additional privileges.