CVE-2013-6768 in Superuser
Summary
by MITRE
Untrusted search path vulnerability in the CyanogenMod/ClockWorkMod/Koush Superuser package 1.0.2.1 for Android 4.2.x and earlier allows attackers to trigger the launch of a Trojan horse app_process program via a crafted PATH environment variable for a /system/xbin/su process.
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Analysis
by VulDB Data Team • 05/09/2026
The vulnerability CVE-2013-6768 represents a critical untrusted search path flaw in the Superuser package implementation used by CyanogenMod, ClockWorkMod, and Koush's tools for Android 4.2.x and earlier versions. This vulnerability resides in the privilege escalation mechanism that governs how the su binary executes with elevated permissions. The affected Superuser package version 1.0.2.1 fails to properly validate or sanitize the PATH environment variable, creating a dangerous condition where an attacker can manipulate the execution environment of the su process. The vulnerability specifically affects the /system/xbin/su process which serves as the core component for granting superuser privileges to applications that require root access.
The technical exploitation of this vulnerability leverages the inherent design flaw in how the su binary resolves executable paths during runtime. When the su process executes, it relies on the PATH environment variable to locate and launch the app_process program, which is responsible for creating the Android runtime environment. An attacker can craft a malicious PATH environment variable that places a Trojan horse app_process binary at a higher precedence location in the search path. This manipulation causes the system to execute the malicious binary instead of the legitimate system app_process, effectively allowing the attacker to inject malicious code into the privileged execution context. This flaw directly maps to CWE-428, which describes untrusted search path vulnerabilities where the system searches for executables in locations that can be manipulated by attackers.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it provides attackers with a pathway to achieve complete system compromise on vulnerable Android devices. Once the malicious app_process binary is executed, the attacker gains full control over the device's privileged operations, enabling them to modify system files, install persistent backdoors, access sensitive user data, and potentially escalate their control to other devices in a networked environment. The vulnerability affects all Android versions up to 4.2.x, which represents a significant portion of the Android ecosystem at the time of discovery, making it particularly dangerous. This type of vulnerability is classified under the ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation" and demonstrates how attackers can leverage weaknesses in system-level components to gain elevated privileges.
Mitigation strategies for CVE-2013-6768 require immediate system updates and configuration changes to address the root cause of the untrusted search path vulnerability. The primary remediation involves updating to newer versions of the Superuser package that properly validate the PATH environment variable and implement secure path resolution techniques. System administrators should also implement proper file permissions and execute-only access controls on system directories to prevent unauthorized binary placement. Additionally, monitoring for suspicious PATH environment variable modifications and implementing application whitelisting policies can help detect and prevent exploitation attempts. The vulnerability highlights the critical importance of secure coding practices in privilege escalation components and demonstrates why proper input validation and environment variable handling are essential security controls in mobile operating systems. Organizations should conduct comprehensive security assessments of their Android device management policies and ensure that all system binaries are properly secured against path manipulation attacks.