CVE-2021-0404 in Android
Summary
by MITRE • 02/27/2021
In mobile_log_d, there is a possible information disclosure due to improper input validation. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation. Product: Android; Versions: Android-11; Patch ID: ALPS05457039.
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Analysis
by VulDB Data Team • 03/05/2021
The vulnerability identified as CVE-2021-0404 resides within the mobile_log_d component of Android systems, specifically affecting Android 11 builds. This issue represents a critical information disclosure weakness that stems from inadequate input validation mechanisms within the logging subsystem. The flaw manifests when the mobile_log_d daemon processes user-supplied data without proper sanitization, creating an avenue for unauthorized information exposure. The vulnerability is classified under CWE-20, which encompasses improper input validation, a fundamental security weakness that has been consistently identified as a primary attack vector in numerous security assessments and penetration testing exercises.
The technical implementation of this vulnerability allows for local information disclosure when an attacker can manipulate input parameters to the mobile_log_d service. This daemon typically handles mobile network logging operations and maintains sensitive operational data about cellular connections, signal strength metrics, and potentially user location information. The exploitation requires System execution privileges, indicating that the vulnerability can be leveraged by processes already running with elevated permissions within the Android security model. This requirement suggests that the vulnerability may be exploited through privilege escalation attacks or by leveraging existing system-level processes that have access to the mobile_log_d functionality. The absence of user interaction requirements makes this particularly concerning as it can be exploited automatically without any manual intervention from the end user.
From an operational perspective, this vulnerability creates significant risks for Android device security and privacy. The local information disclosure could expose sensitive network metadata, potentially including cellular tower information, signal quality data, and other operational parameters that might be used for location tracking or network analysis. Attackers could potentially reconstruct user movement patterns, identify network access points, or gather intelligence about device usage patterns. The implications extend beyond simple data exposure as this information could be combined with other data sources to create comprehensive profiles of user behavior and location history. This vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1005 (Data from Local System) as it enables unauthorized access to system-level information through improper input handling.
The patch provided with ID ALPS05457039 addresses this vulnerability by implementing proper input validation mechanisms within the mobile_log_d component. The fix likely involves sanitizing all input parameters before processing, implementing proper bounds checking, and ensuring that the daemon properly validates data structures before utilizing them in logging operations. Organizations should prioritize applying this patch immediately to all affected Android 11 devices, as the vulnerability can be exploited without user interaction and requires only system-level privileges to execute successfully. Security teams should also monitor for any potential exploitation attempts in their network logs and consider implementing additional monitoring around the mobile_log_d service to detect anomalous behavior patterns that might indicate exploitation attempts. The vulnerability highlights the importance of secure input validation in system-level components and reinforces the need for comprehensive security testing of all services that handle user-provided data within privileged execution contexts.