CVE-2021-0397 in Android
Summary
by MITRE • 03/11/2021
In sdp_copy_raw_data of sdp_discovery.cc, there is a possible system compromise due to a double free. This could lead to remote code execution with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-8.1 Android-9 Android-10Android ID: A-174052148
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Analysis
by VulDB Data Team • 03/31/2021
The vulnerability identified as CVE-2021-0397 represents a critical double free condition within the Bluetooth service discovery protocol implementation of Android operating systems. This flaw exists in the sdp_copy_raw_data function located in the sdp_discovery.cc source file, which forms part of the core Bluetooth stack responsible for service discovery and data handling within the Android framework. The double free vulnerability occurs when memory allocated for service discovery protocol data is freed twice during the processing of Bluetooth service records, creating a scenario where an attacker can manipulate the heap memory layout and potentially execute arbitrary code.
The technical exploitation of this vulnerability leverages heap corruption principles that align with CWE-415, which specifically addresses double free conditions in memory management. When the Bluetooth service discovery process encounters malformed or specially crafted service records, the sdp_copy_raw_data function fails to properly track memory allocations, leading to a situation where the same memory block can be freed twice. This memory management error creates opportunities for attackers to manipulate heap metadata, potentially leading to remote code execution without requiring any additional privileges or user interaction. The vulnerability affects multiple Android versions including Android 8.1, 9, 10, and 11, indicating a widespread impact across the Android ecosystem.
The operational impact of CVE-2021-0397 extends beyond simple privilege escalation as it represents a remote code execution vulnerability that can be triggered through Bluetooth service discovery interactions. Attackers can exploit this vulnerability by establishing a Bluetooth connection to a target device and sending malicious service discovery protocol data that triggers the double free condition. This capability allows for full system compromise without requiring physical access or user interaction, making it particularly dangerous in environments where Bluetooth connectivity is prevalent. The vulnerability's classification under the Android ID A-174052148 demonstrates the severity recognized by Google's security team, as it can be exploited remotely through Bluetooth connections and potentially lead to complete device compromise.
Mitigation strategies for CVE-2021-0397 should prioritize immediate patch deployment through official Android security updates, as this vulnerability has been addressed in subsequent Android security releases. Organizations should implement Bluetooth network segmentation and monitoring to detect potential exploitation attempts, while also considering temporary Bluetooth service disabling in high-security environments. The vulnerability's exploitation mechanism aligns with ATT&CK technique T1059.007 for remote code execution through system services, making traditional network security controls insufficient. Security teams should monitor for unusual Bluetooth service discovery patterns and implement memory corruption detection mechanisms to identify potential exploitation attempts. Additionally, regular security audits of Bluetooth service implementations and proper input validation for service discovery protocol data should be enforced to prevent similar vulnerabilities from emerging in future implementations.