CVE-2005-0627 in qt
Summary
by MITRE
qt before 3.3.4 searches the build_prefix directory which could be world-writable to load shared libraries regardless of the ld_library_path environment variable which allows local users to execute arbitrary programs.
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Analysis
by VulDB Data Team • 07/01/2021
The vulnerability described in CVE-2005-0627 represents a critical security flaw in the Qt graphical toolkit library versions prior to 3.3.4. This issue stems from improper handling of library loading mechanisms within the Qt framework, creating a significant attack surface for local privilege escalation. The flaw specifically affects systems where the build_prefix directory is world-writable, allowing malicious actors to exploit the library loading behavior to execute arbitrary code with elevated privileges.
The technical root cause of this vulnerability lies in Qt's library search order implementation. When Qt applications attempt to load shared libraries, they traverse directories in a specific order that does not properly respect the ld_library_path environment variable. This behavior creates a path traversal vulnerability where the system will load libraries from the build_prefix directory even when that directory has world-writable permissions. The vulnerability manifests because Qt's implementation fails to validate directory permissions before attempting library loading, effectively bypassing normal security controls that would normally prevent loading of malicious libraries from insecure locations.
This flaw operates under the principle of insecure library loading as classified by CWE-427, where applications fail to properly control the search path for dynamic libraries. The operational impact of this vulnerability is severe as it allows local users to gain unauthorized code execution capabilities without requiring special privileges. Attackers can place malicious shared libraries in the world-writable build_prefix directory, which will then be loaded by Qt applications running with higher privileges, potentially leading to privilege escalation attacks. The vulnerability affects any system running Qt applications where the build_prefix directory has insecure permissions, making it particularly dangerous in multi-user environments.
The attack vector for this vulnerability requires local system access and knowledge of the Qt application architecture. The exploit involves placing a malicious shared library in the world-writable build_prefix directory, which then gets loaded by Qt applications during execution. This technique aligns with ATT&CK tactics related to privilege escalation and persistence through library injection. The vulnerability demonstrates poor security practices in library loading mechanisms and highlights the importance of proper permission checking and secure coding practices in system libraries.
Mitigation strategies for this vulnerability include updating to Qt version 3.3.4 or later, which contains the necessary fixes for proper library loading behavior. System administrators should also ensure that build_prefix directories and other system directories used for library loading have appropriate permissions to prevent world-writable access. Additionally, implementing proper library path validation and using secure coding practices that respect environment variables like ld_library_path can prevent similar issues. The fix implemented in Qt 3.3.4 addresses the core issue by ensuring that library loading respects directory permissions and environment variable settings, preventing the loading of malicious libraries from insecure locations. Organizations should also conduct regular security audits to identify and remediate similar vulnerabilities in their software dependencies.