CVE-2023-21387 in Android
Summary
by MITRE • 10/30/2023
In User Backup Manager, there is a possible way to leak a token to bypass user confirmation for backup due to log information disclosure. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/22/2023
The vulnerability identified as CVE-2023-21387 resides within the User Backup Manager component where improper handling of authentication tokens creates a significant security risk. This flaw manifests through log information disclosure mechanisms that inadvertently expose sensitive authentication tokens used for backup operations. The vulnerability operates at the intersection of improper logging practices and authentication bypass mechanisms, creating a pathway for unauthorized access to backup systems without requiring user interaction or confirmation. The technical implementation appears to store or transmit authentication tokens in log files with insufficient sanitization or access controls, allowing potential attackers to extract these credentials through routine log file access or monitoring activities.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass complete system compromise when combined with system execution privileges. Attackers leveraging this vulnerability can bypass user confirmation prompts that are typically required for backup operations, effectively gaining unauthorized access to backup functionalities. This represents a critical escalation from information disclosure to privilege escalation, as the leaked tokens can be used to perform backup operations with elevated system privileges. The vulnerability's design flaw allows for automated exploitation without requiring any user interaction, making it particularly dangerous in environments where backup operations are frequently performed or where automated backup processes are in place.
From a cybersecurity perspective, this vulnerability aligns with CWE-209, which addresses information exposure through log data, and CWE-359, which covers exposure of private information in logs. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under T1070.004 for Indicator Removal on Host and T1566 for Phishing, as the vulnerability enables attackers to bypass security controls that would normally require user interaction. The lack of user interaction requirement places this vulnerability in a particularly dangerous category, as it can be exploited silently during normal system operations without detection by standard user awareness mechanisms.
Mitigation strategies should focus on implementing comprehensive log sanitization procedures that prevent authentication tokens and sensitive credentials from being written to log files. Organizations should establish strict access controls for log files, ensuring that only authorized system administrators can access these resources. The implementation of token rotation mechanisms and automatic token invalidation should be prioritized to minimize the window of opportunity for exploitation. Additionally, system administrators should conduct regular log file audits to identify and remove any previously leaked tokens. Network segmentation and monitoring solutions should be deployed to detect unusual backup access patterns that might indicate exploitation attempts. The vulnerability also underscores the importance of following secure coding practices that prevent sensitive data exposure in any system output, including logs, error messages, and debugging information.