CVE-2022-20224 in Android
Summary
by MITRE • 07/13/2022
In AT_SKIP_REST of bta_hf_client_at.cc, there is a possible out of bounds read due to an incorrect bounds check. This could lead to remote information disclosure in the Bluetooth stack with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-12LAndroid ID: A-220732646
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Analysis
by VulDB Data Team • 07/31/2022
The vulnerability identified as CVE-2022-20224 resides within the Bluetooth stack implementation of Android operating systems, specifically affecting versions 10 through 12L. This issue manifests in the bta_hf_client_at.cc source file where the AT_SKIP_REST function contains a flawed bounds checking mechanism that permits out-of-bounds memory reads. The vulnerability represents a critical security flaw that could potentially enable unauthorized information disclosure without requiring any additional privileges or user interaction for exploitation. The affected Android versions span multiple releases including Android 10, 11, 12, and 12L, indicating this flaw has persisted across several major releases of the platform. The vulnerability operates at the Bluetooth Hands-Free profile client level, where AT commands are processed, making it particularly concerning for devices that utilize Bluetooth audio functionality. This type of out-of-bounds read vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions that can lead to information disclosure and potentially more severe consequences. The Android ID A-220732646 further documents this specific issue within Google's internal tracking system, highlighting its severity and the need for immediate attention.
The technical implementation flaw occurs when processing AT commands within the Bluetooth Hands-Free profile client context. The AT_SKIP_REST function fails to properly validate array bounds during command parsing operations, creating a scenario where memory reads can extend beyond allocated buffer boundaries. This incorrect bounds checking allows an attacker to potentially access adjacent memory locations that may contain sensitive data such as cryptographic keys, user credentials, or other confidential information stored in the device's memory. The vulnerability's exploitation requires no user interaction, meaning it can be triggered remotely through Bluetooth communication without any physical access or user consent. This characteristic significantly increases the attack surface and makes the vulnerability particularly dangerous in environments where Bluetooth devices are frequently connected or where devices operate in public spaces. The flaw exists within the Bluetooth stack's parsing logic, which processes incoming AT commands from remote Bluetooth devices, making it a potential vector for information leakage attacks.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially compromise the overall security posture of affected Android devices. Remote attackers could exploit this vulnerability to extract sensitive data from the device's memory, which might include session tokens, encryption keys, or personal information. The lack of required user interaction means that devices could be compromised simply by being within range of an attacker's Bluetooth transmitter. This vulnerability affects the fundamental Bluetooth security model of Android devices, potentially undermining trust in Bluetooth-based connections and services. The implications are particularly severe for devices that frequently connect to Bluetooth audio systems, automotive infotainment systems, or other Bluetooth-enabled peripherals where sensitive information might be stored in memory. The vulnerability's presence across multiple Android versions indicates that a substantial portion of the Android ecosystem could be at risk, requiring urgent patching and mitigation strategies across affected device fleets. Security researchers categorize this type of vulnerability under the ATT&CK technique T1059.001 for command and scripting interpreter, specifically targeting the Bluetooth stack as a means of information gathering.
Mitigation strategies for CVE-2022-20224 should prioritize immediate deployment of security patches provided by Google and device manufacturers. Organizations should implement network segmentation to limit Bluetooth connectivity where possible, particularly in enterprise environments where sensitive data is prevalent. Device administrators should consider disabling Bluetooth functionality when not actively needed and ensure that automatic pairing features are disabled. Regular security audits should be conducted to identify any unauthorized Bluetooth connections or suspicious device pairing activities. The vulnerability's classification as a memory safety issue suggests that additional runtime protections such as address space layout randomization and stack canaries should be considered as supplementary defenses. Mobile device management solutions should be configured to enforce automatic security updates for Bluetooth stack components. Security teams should monitor for any reported exploitation attempts or related vulnerabilities that might be leveraged in conjunction with this flaw. Device manufacturers should consider implementing additional bounds checking mechanisms in their Bluetooth stack implementations to prevent similar vulnerabilities from emerging in future releases. The remediation process should include comprehensive testing to ensure that security patches do not introduce regressions in Bluetooth functionality while effectively addressing the memory access violation.