CVE-2017-13287 in Android
Summary
by MITRE
In createFromParcel of VerifyCredentialResponse.java, there is a possible invalid parcel read due to improper input validation. This could lead to local escalation of privilege if mPayload in writeToParcel were null, with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android. Versions: 6.0.1, 7.0, 7.1.1, 7.1.2, 8.0, 8.1. Android ID: A-71714464.
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Analysis
by VulDB Data Team • 01/21/2020
The vulnerability identified as CVE-2017-13287 resides within the Android system's credential verification mechanism, specifically in the createFromParcel method of the VerifyCredentialResponse.java class. This flaw represents a classic improper input validation issue that can be categorized under CWE-252, which deals with unchecked return values. The vulnerability manifests when the system processes parcelable objects containing credential verification responses, creating a potential pathway for privilege escalation attacks that do not require user interaction or additional execution privileges to exploit.
The technical implementation flaw occurs in the parcel read operation where the system fails to properly validate input data before processing it. When mPayload is written to the parcel using writeToParcel and subsequently becomes null, the createFromParcel method does not adequately check for this condition before attempting to read from the parcel. This improper validation creates a scenario where the system might attempt to access invalid memory locations or process malformed data structures. The vulnerability is particularly concerning because it operates at the system level within Android's security framework, where credential verification responses are handled with elevated privileges.
The operational impact of this vulnerability extends to local privilege escalation, allowing an attacker with a low-privilege process to potentially elevate their privileges to system level. This occurs because the verification credential response mechanism is designed to handle sensitive security data, and when the parcel read operation fails due to improper validation, it creates an opportunity for malicious code execution. The attack vector requires no user interaction, making it particularly dangerous as it can be exploited automatically without any user awareness or consent. This characteristic places the vulnerability in the ATT&CK framework under privilege escalation techniques where adversaries can leverage system-level vulnerabilities to gain elevated access rights.
The exploitation of this vulnerability demonstrates the critical importance of proper input validation in security-critical code paths. When the mPayload field becomes null during the parcel writing process, the subsequent read operation in createFromParcel can lead to memory corruption or other undefined behaviors that attackers can potentially leverage for privilege escalation. The vulnerability affects multiple Android versions including 6.0.1, 7.0, 7.1.1, 7.1.2, 8.0, and 8.1, indicating a widespread issue within the Android security architecture. The Android ID A-71714464 specifically tracks this vulnerability and highlights its severity within the Android security ecosystem. Organizations and users must understand that this flaw represents a fundamental breakdown in the Android security model's validation mechanisms, particularly in how the system handles credential verification responses. The vulnerability underscores the necessity of comprehensive input validation across all security-critical code paths, especially those dealing with sensitive authentication data and system-level operations. Mitigation efforts should focus on implementing proper null checks and input validation before attempting to read from parcelable objects, ensuring that the system can gracefully handle edge cases and malformed data without compromising security boundaries.