CVE-2016-6935 in Creative Cloud Desktop Application
Summary
by MITRE
Unquoted Windows search path vulnerability in Adobe Creative Cloud Desktop Application before 3.8.0.310 on Windows allows local users to gain privileges via a Trojan horse executable file in the %SYSTEMDRIVE% directory.
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Analysis
by VulDB Data Team • 09/24/2024
The vulnerability identified as CVE-2016-6935 represents a critical unquoted search path weakness in Adobe Creative Cloud Desktop Application versions prior to 3.8.0.310 on Windows systems. This flaw stems from improper handling of executable paths during the application's startup process, creating a privilege escalation vector that adversaries can exploit. The vulnerability specifically affects the Windows operating system's path resolution mechanism where the system searches for executables in a predetermined order without requiring explicit quotation marks around paths containing spaces. When an application fails to properly quote paths containing spaces, Windows performs a left-to-right search through the PATH environment variable, potentially executing malicious code placed in directories with unquoted paths.
The technical implementation of this vulnerability involves the Adobe Creative Cloud Desktop Application's failure to properly quote executable paths in its Windows service or startup routines. When the application attempts to locate and execute supporting binaries, it does not enforce proper path quoting, allowing the Windows shell to interpret the path components separately. This creates a scenario where a malicious actor can place a Trojan horse executable file in the %SYSTEMDRIVE% directory, which typically corresponds to the C: drive root. Since the Windows search path includes this directory and the application does not properly quote its executable paths, the system will execute the malicious file instead of the intended legitimate application component. This behavior directly aligns with CWE-428, which describes "Unquoted Search Path" vulnerabilities where the operating system searches for executables in a path without proper quoting, and is classified as a privilege escalation vulnerability under the MITRE ATT&CK framework.
The operational impact of this vulnerability extends beyond simple local privilege escalation to potentially enable persistent malware persistence on compromised systems. Local users who can write to the %SYSTEMDRIVE% directory can leverage this weakness to install malicious software that executes with elevated privileges. The attack vector requires local system access and the ability to place files in the system drive root directory, but does not require administrative privileges for the initial exploitation. This makes the vulnerability particularly dangerous in enterprise environments where users might have local access to systems but lack administrative rights. The malicious executable can potentially establish persistence mechanisms, escalate privileges further, or serve as a launch point for more sophisticated attacks. The vulnerability is especially concerning because it operates silently without user interaction and can be difficult to detect through standard security monitoring.
Mitigation strategies for CVE-2016-6935 involve multiple layers of defense including immediate patching of affected Adobe Creative Cloud Desktop Application versions to 3.8.0.310 or later, which properly implements quoted search paths. System administrators should conduct comprehensive inventory checks to identify all affected installations and ensure proper patch deployment across enterprise environments. Additional protective measures include implementing strict file system permissions on the %SYSTEMDRIVE% directory to prevent unauthorized modifications, monitoring for suspicious executable placement in system directories, and employing application whitelisting solutions that prevent execution of unauthorized binaries. Security teams should also review and harden the Windows PATH environment variable to minimize the presence of directories with insufficient access controls. The vulnerability demonstrates the critical importance of proper path handling in application development and aligns with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks, emphasizing the need for secure coding practices and proper input validation to prevent such path traversal and privilege escalation vulnerabilities.