CVE-2016-10428 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Automobile and Snapdragon Mobile SD 425, SD 430, SD 450, SD 625, SD 650/52, SD 820, and SD 820A, HMAC verification in counter file uses an insecure memcmp which may assist a timing attack.
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Analysis
by VulDB Data Team • 01/27/2020
This vulnerability affects Android devices running before the 2018-04-05 security patch level on Qualcomm Snapdragon automotive and mobile platforms including the SD 425, SD 430, SD 450, SD 625, SD 650/52, SD 820, and SD 820A chipsets. The issue stems from an insecure implementation of HMAC verification within counter file operations where the system employs a vulnerable memcmp function that does not provide constant-time comparison behavior. This flaw creates a timing attack vector that allows adversaries to potentially infer sensitive cryptographic information through analysis of processing time variations during authentication operations. The vulnerability specifically impacts the cryptographic integrity checks that are fundamental to maintaining secure authentication mechanisms in automotive and mobile environments where device security is paramount.
The technical flaw manifests in the cryptographic verification process where HMAC (Hash-based Message Authentication Code) verification routines utilize a standard memcmp function instead of a constant-time comparison implementation. This design choice enables timing attacks that exploit the differential execution times of the comparison operation based on the number of matching bytes at the beginning of the compared data. In cryptographic contexts, such timing variations can reveal information about the expected authentication values, potentially allowing attackers to reconstruct valid HMAC signatures through repeated observations and statistical analysis. The vulnerability is classified under CWE-203: Observable Behavioral Vulnerability, which specifically addresses weaknesses where the behavior of a system reveals sensitive information through timing or other observable characteristics.
The operational impact of this vulnerability extends significantly in automotive and mobile security contexts where authentication systems rely on HMAC verification for protecting critical functions such as vehicle access control, secure communication protocols, and device integrity checks. Attackers with local access or network proximity could exploit this vulnerability to perform credential harvesting attacks, potentially gaining unauthorized access to vehicle systems, compromising secure communication channels, or undermining the integrity of device authentication processes. The timing attack nature of this vulnerability means that even minimal computational resources could be sufficient to gather enough timing information to mount successful attacks, making it particularly dangerous in environments where physical access to devices may be possible.
Mitigation strategies for this vulnerability require immediate deployment of the relevant Android security patches released in the 2018-04-05 update cycle, which address the insecure memcmp implementation by replacing it with constant-time comparison functions. Organizations should also implement monitoring systems to detect anomalous timing patterns in authentication processes that could indicate exploitation attempts. The fix aligns with ATT&CK technique T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) through improved cryptographic implementation practices that prevent timing-based information leakage. Additional defensive measures include implementing proper input validation, utilizing hardware security modules where possible, and conducting regular security assessments of cryptographic implementations. System administrators should prioritize patch management processes to ensure all affected devices receive the necessary updates, particularly in automotive environments where security is critical for passenger safety and vehicle integrity.