CVE-2014-7951 in Android
Summary
by MITRE
Directory traversal vulnerability in the Android debug bridge (aka adb) in Android 4.0.4 allows physically proximate attackers with a direct connection to the target Android device to write to arbitrary files owned by system via a .. (dot dot) in the tar archive headers.
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Analysis
by VulDB Data Team • 07/30/2024
The vulnerability identified as CVE-2014-7951 represents a critical directory traversal flaw within the Android Debug Bridge (adb) component of Android 4.0.4 systems. This security weakness specifically targets the extraction process of tar archives and enables attackers to manipulate file system permissions and write to arbitrary locations on the device. The vulnerability is particularly concerning because it requires only physical proximity to the target device and a direct connection, making it accessible to attackers who can physically access the Android device. The attack vector exploits the insecure handling of directory traversal sequences within tar archive headers, specifically the ".." (dot dot) sequences that are commonly used to navigate up directory levels.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the adb service during tar archive extraction operations. When adb processes tar archives containing directory traversal sequences in their headers, it fails to properly validate or sanitize these paths before performing file operations. This allows an attacker to manipulate the extraction process to write files to locations outside the intended target directory. The flaw is categorized under CWE-22 as "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')" which is a well-known vulnerability pattern in software systems. The vulnerability specifically affects the adb service which operates with elevated privileges on Android devices, making the potential impact significantly more severe.
Operationally, this vulnerability creates a serious risk for Android 4.0.4 devices as it allows attackers with physical access to compromise system integrity and potentially escalate privileges. The ability to write arbitrary files owned by the system creates opportunities for persistent backdoors, data exfiltration, or system corruption. Attackers could leverage this vulnerability to modify critical system files, install malicious applications, or establish persistent access points on the device. The attack requires minimal prerequisites beyond physical proximity and direct connection, making it particularly dangerous in environments where device security is not properly enforced. This vulnerability is classified under the ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1078.004 for Valid Accounts - Default Accounts, as it exploits legitimate system services to gain unauthorized access to system resources.
Mitigation strategies for CVE-2014-7951 should focus on immediate system updates and operational security measures. The primary recommendation is to upgrade to Android versions that contain patches for this vulnerability, as the issue was addressed in subsequent releases. Organizations should implement strict access controls and device security policies to prevent unauthorized physical access to Android devices. Network segmentation and monitoring should be employed to detect suspicious adb activity or unauthorized file system modifications. System administrators should disable adb debugging services when not actively required for development or maintenance purposes, as this reduces the attack surface. Additionally, implementing file integrity monitoring solutions can help detect unauthorized modifications to critical system files that might result from exploitation of this vulnerability. The vulnerability highlights the importance of secure coding practices and proper input validation in system services that handle user-supplied data, particularly those operating with elevated privileges.