CVE-2021-0997 in Android
Summary
by MITRE • 12/15/2021
In handleUpdateNetworkState of GnssNetworkConnectivityHandler.java , there is a possible APN disclosure due to log information disclosure. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-191086488
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-0997 resides within the Android operating system's location services implementation, specifically in the GnssNetworkConnectivityHandler.java component. This flaw represents a sensitive information disclosure issue that occurs during the handling of network state updates for Global Navigation Satellite System connectivity. The vulnerability manifests when the system logs network connectivity information containing potentially sensitive Access Point Name (APN) data during the execution of the handleUpdateNetworkState method. This represents a classic information exposure vulnerability that falls under the CWE-209 category for exposure of system information to an unauthorized actor. The issue is particularly concerning because it allows for local information disclosure without requiring any additional privileges or user interaction, making it an attractive target for malicious actors who may already have limited access to the device.
The technical implementation flaw stems from improper handling of logging operations within the GNSS network connectivity management framework. When the system processes network state changes, it inadvertently includes APN information in log output that should remain confidential. This logging behavior exposes sensitive network configuration data that could potentially be leveraged by attackers to understand the device's network connectivity profile and potentially identify other security weaknesses. The vulnerability operates at the system level within Android's connectivity services, specifically affecting the Android 12 operating system version where this flaw was present. The Android ID A-191086488 identifies this specific issue within Google's internal tracking system and indicates the severity level of the vulnerability.
The operational impact of CVE-2021-0997 extends beyond simple information disclosure as it provides attackers with insights into the device's network configuration and connectivity patterns. While the vulnerability does not require additional execution privileges or user interaction, it creates a potential attack vector that could be combined with other weaknesses to escalate privileges or conduct further reconnaissance. The exposure of APN information could enable attackers to understand network filtering rules, carrier configurations, or even identify potential network-based attack surfaces. This vulnerability aligns with ATT&CK technique T1082 for system information discovery and T1566 for credential access through network-based reconnaissance. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited silently in the background without the user's knowledge or consent.
Mitigation strategies for CVE-2021-0997 should focus on implementing proper logging controls and sanitizing sensitive information before it reaches log output systems. Device manufacturers and system administrators should ensure that all network connectivity logging operations properly filter out sensitive data including APN information, usernames, and passwords. The recommended approach involves updating to the latest Android security patches that address this specific vulnerability, as Google would have released a fix for this issue in their regular security updates. Additionally, implementing log monitoring systems that can detect and alert on unusual logging patterns containing sensitive information would provide an additional layer of defense. Organizations should also consider implementing mobile device management policies that restrict logging capabilities for sensitive system components and ensure that any debugging or logging features are properly configured to prevent information leakage. The vulnerability demonstrates the importance of proper input validation and output sanitization in system components handling network configuration data, aligning with security best practices outlined in OWASP and NIST cybersecurity guidelines.