CVE-2023-29736 in Keyboard Themes
Summary
by MITRE • 06/02/2023
Keyboard Themes 1.275.1.164 for Android contains a dictionary traversal vulnerability that allows unauthorized apps to overwrite arbitrary files in its internal storage and achieve arbitrary code execution.
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Analysis
by VulDB Data Team • 12/14/2025
The vulnerability identified as CVE-2023-29736 affects Keyboard Themes version 1.275.1.164 for Android devices, representing a critical security flaw that enables malicious applications to exploit dictionary traversal mechanisms within the keyboard application's internal storage. This vulnerability specifically resides in the file system access controls and path resolution logic of the keyboard theme component, which fails to properly validate user-supplied input during file operations. The issue stems from inadequate sanitization of file paths that allows attackers to manipulate the traversal sequences and access restricted storage areas. According to CWE-22, this vulnerability maps directly to path traversal attacks where an attacker can manipulate file paths to access or modify files outside of the intended directory structure. The affected application's internal storage directory structure appears to lack proper boundary checks, enabling attackers to navigate beyond the designated storage boundaries through crafted input sequences. This weakness creates a pathway for unauthorized file manipulation and potentially complete system compromise.
The technical implementation of this vulnerability exploits the keyboard application's failure to properly validate or sanitize file paths during theme installation or processing operations. When the application processes theme files or configuration data, it accepts user-provided paths without adequate validation, allowing attackers to inject malicious traversal sequences such as ../ or ..\ that can navigate to parent directories. The vulnerability manifests when the application attempts to access or write files in its internal storage, where it fails to enforce proper access controls or path validation. This flaw allows an attacker to overwrite existing files or create new files in locations that should normally be restricted, potentially including system directories or other application storage areas. The underlying mechanism likely involves the application using standard file system APIs without proper input sanitization, creating an environment where path traversal attacks can succeed. The vulnerability demonstrates poor secure coding practices and violates fundamental principles of input validation and access control enforcement. From an ATT&CK perspective, this vulnerability aligns with techniques such as T1059.007 for command and script interpreter execution, as successful exploitation could enable code execution through file overwrites in system directories.
The operational impact of CVE-2023-29736 extends beyond simple file system compromise to potentially enable complete system compromise through arbitrary code execution. An attacker who successfully exploits this vulnerability can overwrite critical system files, install malicious payloads, or modify application behavior to gain persistent access to the device. The ability to overwrite arbitrary files in internal storage creates opportunities for privilege escalation attacks, where malicious code can be injected into system processes or replace legitimate application components. This vulnerability particularly affects Android devices where keyboard applications have elevated privileges and access to sensitive user data. The exploitation chain typically involves installing a malicious application that leverages the keyboard theme component's vulnerability to place malicious files in strategic locations within the device's file system. The vulnerability's impact is amplified by the fact that keyboard applications often have access to user input data, making successful exploitation potentially devastating for user privacy and device security. Additionally, the vulnerability could enable attackers to modify or replace keyboard themes with malicious variants, creating a persistent backdoor for data collection or further attacks. Organizations and users should consider this vulnerability as a potential entry point for more sophisticated attacks targeting device integrity and user data protection. The vulnerability's severity classification reflects its potential for remote code execution and system compromise, making it a high-priority concern for mobile security teams and enterprise device management programs.