CVE-2018-4051 in Galaxy
Summary
by MITRE
An exploitable local privilege escalation vulnerability exists in the privileged helper tool of GOG Galaxy's Games, version 1.2.47 for macOS. An attacker can globally create directories and subdirectories on the root file system, as well as change the permissions of existing directories.
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Analysis
by VulDB Data Team • 08/21/2023
The vulnerability described in CVE-2018-4051 represents a critical local privilege escalation flaw within GOG Galaxy's privileged helper tool on macOS systems. This issue stems from improper access controls and privilege management within the software's helper tool implementation, which operates with elevated privileges to perform system-level operations. The vulnerability specifically affects version 1.2.47 of the GOG Galaxy client, indicating a targeted flaw in the application's privilege escalation mechanisms that allows unprivileged users to gain root-level access to the system. The security implications are severe as this flaw enables attackers to manipulate the core file system structure through the helper tool's interface.
The technical root cause of this vulnerability lies in the insufficient validation and sanitization of paths and permissions within the privileged helper tool's execution context. When the helper tool processes certain operations, it fails to properly verify the integrity of directory creation requests or permission changes, allowing attackers to specify arbitrary paths that would normally require administrative privileges to modify. This flaw specifically enables global directory creation and permission modification operations on the root file system, bypassing normal macOS security mechanisms such as sandboxing and privilege separation. The vulnerability operates through the helper tool's communication interface, where attacker-controlled inputs can be passed directly to system-level file operations without proper authorization checks.
The operational impact of this vulnerability extends far beyond simple file system manipulation, as it provides complete system compromise capabilities for local attackers. An attacker with low-privilege access can leverage this flaw to establish persistent backdoors, install malicious software, modify system binaries, and potentially escalate to full administrative control. The ability to globally create directories and modify permissions on the root file system means attackers can manipulate critical system paths, create hidden directories for persistence, and alter security-related file permissions. This vulnerability directly violates the principle of least privilege and demonstrates a failure in the application's privilege management architecture. The flaw also enables potential exploitation of other system vulnerabilities through the creation of malicious file structures that can be triggered by system processes or other applications.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected GOG Galaxy client version, as well as implementing additional security controls within the macOS environment. System administrators should ensure that all GOG Galaxy installations are updated to versions that address this privilege escalation flaw, typically through official software updates from GOG. The vulnerability aligns with CWE-276, which covers improper privilege management, and represents a clear violation of the principle of least privilege. Organizations should also consider implementing additional monitoring of system file changes and privileged helper tool usage to detect potential exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be used to establish persistence through file system manipulation. The remediation process should include verification that the helper tool operates with minimal required privileges and that all file system operations are properly validated against the executing user's permissions.