CVE-2024-43093: Android Privilege Escalation Vulnerability

CVE-2024-43093 Overview

CVE-2024-43093 is a local privilege escalation vulnerability in Google Android's ExternalStorageProvider.java component. The flaw exists in the shouldHideDocument function, where incorrect Unicode normalization allows attackers to bypass file path filters designed to prevent access to sensitive directories. This vulnerability has been actively exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities catalog.

The vulnerability enables a malicious application to circumvent Android's security controls that normally protect sensitive system directories from unauthorized access. By exploiting Unicode normalization inconsistencies, an attacker can craft file paths that evade the security filter while still resolving to protected locations.

Critical Impact

This vulnerability is actively exploited in the wild and listed in CISA's Known Exploited Vulnerabilities catalog. Successful exploitation allows local privilege escalation, enabling unauthorized access to sensitive directories on affected Android devices without requiring additional execution privileges.

Affected Products

• Google Android 12.0
• Google Android 12.1
• Google Android 13.0
• Google Android 14.0
• Google Android 15.0

Discovery Timeline

• November 13, 2024 - CVE-2024-43093 published to NVD
• October 23, 2025 - Last updated in NVD database

Technical Details for CVE-2024-43093

Vulnerability Analysis

The vulnerability resides in the shouldHideDocument method within Android's ExternalStorageProvider.java. This function is responsible for determining whether a document path should be hidden from external applications, serving as a critical security boundary to protect sensitive system directories from unauthorized access.

The root cause is an improper handling of Unicode normalization during file path validation. Unicode normalization is the process of converting Unicode text to a canonical form, which is essential for consistent string comparison. Android's file path filter fails to properly normalize Unicode characters before performing security checks, creating a discrepancy between what the filter validates and what the file system actually resolves.

An attacker can leverage this by constructing file paths using Unicode characters that normalize to different forms. The security filter checks the pre-normalized path (which appears benign), while the file system resolves the post-normalized path (which points to a sensitive directory). This classic normalization bypass allows circumvention of directory access restrictions.

Root Cause

The vulnerability stems from CWE-176: Improper Handling of Unicode Encoding. The shouldHideDocument function does not apply consistent Unicode normalization when comparing file paths against the list of protected directories. This allows specially crafted Unicode sequences to bypass the filter while still resolving to restricted paths on the underlying file system.

Attack Vector

The attack requires local access and user interaction for exploitation. A malicious application installed on the device can exploit this vulnerability by:

1. Crafting a file path using Unicode characters that bypass the shouldHideDocument security check
2. Requesting access to the crafted path through Android's document provider interface
3. The path passes the security filter due to Unicode normalization differences
4. The file system resolves the normalized path, granting access to sensitive directories
5. The attacker gains access to protected files, enabling privilege escalation

The vulnerability is particularly concerning because it requires no additional execution privileges beyond what a normal application would have, and the user interaction required could be as simple as opening a malicious application or document.

Detection Methods for CVE-2024-43093

Indicators of Compromise

• Unusual file access patterns involving Unicode characters in path names targeting system directories
• Applications attempting to access /Android/data, /Android/obb, or other protected directories through the ExternalStorageProvider
• Log entries showing document provider requests with non-ASCII or unusual Unicode sequences in file paths
• Evidence of unauthorized access to application-specific storage directories

Detection Strategies

• Monitor ExternalStorageProvider activity for requests containing Unicode characters that could indicate normalization bypass attempts
• Implement application behavior analysis to detect apps requesting access to sensitive directories through unusual path constructions
• Review device logs for suspicious document provider interactions, particularly those involving file paths with Unicode normalization forms
• Deploy mobile threat detection solutions capable of identifying privilege escalation attempts on Android devices

Monitoring Recommendations

• Enable verbose logging for document provider activities on managed Android devices
• Utilize SentinelOne's mobile threat defense capabilities to detect and block exploitation attempts
• Monitor for known exploit patterns associated with CVE-2024-43093 in enterprise mobile device management (MDM) solutions
• Implement behavioral analysis for installed applications to detect anomalous file system access patterns

How to Mitigate CVE-2024-43093

Immediate Actions Required

• Update all affected Android devices to the latest security patch level (March 2025 security bulletin or later)
• Organizations should prioritize patching given the vulnerability's inclusion in CISA's Known Exploited Vulnerabilities catalog
• Audit installed applications on managed devices to identify potentially malicious apps
• Enable Google Play Protect and ensure it is actively scanning devices for threats

Patch Information

Google has released patches addressing this vulnerability through the Android Security Bulletin March 2025. The fix is available in the Android source code repository with commit hash 7f83c671626f9bf993581f4598c22482d87cba10.

The patch corrects the Unicode normalization handling in the shouldHideDocument function, ensuring consistent normalization is applied before security checks are performed. Device manufacturers should incorporate this patch into their Android builds, and end users should update to the latest available security patch level for their device.

Workarounds

• Limit installation of applications to trusted sources (Google Play Store) until patches can be applied
• Utilize Android Enterprise work profiles to isolate sensitive data from potentially vulnerable personal applications
• Implement application allowlisting on managed devices to prevent execution of unauthorized applications
• Consider temporarily restricting external storage access permissions for non-essential applications

# Verify Android security patch level via ADB
adb shell getprop ro.build.version.security_patch
# Output should show 2025-03-01 or later for patched devices

# Check for ExternalStorageProvider-related activity in logs
adb logcat | grep -i "ExternalStorageProvider"