CVE-2015-7888 in S6 Edge
Summary
by MITRE
Directory traversal vulnerability in the WifiHs20UtilityService on the Samsung S6 Edge LRX22G.G925VVRU1AOE2 allows remote attackers to overwrite or create arbitrary files as the system-level user via a .. (dot dot) in the name of a file, compressed into a zipped file named cred.zip, and downloaded to /sdcard/Download.
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Analysis
by VulDB Data Team • 12/08/2022
The CVE-2015-7888 vulnerability represents a critical directory traversal flaw within the WifiHs20UtilityService component of Samsung's S6 Edge device running firmware version LRX22G.G925VVRU1AOE2. This vulnerability exists within the system's handling of compressed files and file naming conventions, specifically when processing files downloaded to the /sdcard/Download directory. The flaw stems from inadequate input validation and path resolution mechanisms that fail to properly sanitize file names containing directory traversal sequences. Attackers can exploit this weakness by crafting a malicious zip file named cred.zip that contains files with .. (dot dot) sequences in their names, enabling them to manipulate the file system outside of intended directories.
The technical execution of this vulnerability relies on the system's failure to properly validate file paths during decompression operations. When the WifiHs20UtilityService processes the malicious zip file, it does not adequately sanitize the file names contained within the archive, allowing directory traversal sequences to be interpreted as legitimate path navigation commands. This results in the system creating or overwriting files in arbitrary locations with system-level privileges, effectively bypassing normal file system access controls and permissions. The vulnerability operates at the operating system level, leveraging the service's elevated privileges to execute arbitrary file system operations.
The operational impact of CVE-2015-7888 is severe as it provides remote attackers with the ability to execute arbitrary file system operations with system-level privileges. This capability enables attackers to overwrite critical system files, inject malicious code into the operating system, or create persistent backdoors on affected devices. The vulnerability is particularly dangerous because it operates silently in the background, requiring no user interaction beyond downloading the malicious zip file. The affected service runs with elevated privileges, meaning that successful exploitation results in complete system compromise. This vulnerability aligns with CWE-22 Directory Traversal and represents a classic example of improper input validation leading to privilege escalation.
From a cybersecurity perspective, this vulnerability demonstrates the critical importance of proper input sanitization and privilege separation in mobile operating systems. The attack vector represents a sophisticated technique that combines social engineering with system-level exploitation, making it particularly dangerous in real-world scenarios. Organizations should consider implementing network-based protections and monitoring for suspicious file download patterns, while the vulnerability itself requires immediate patching and firmware updates. The issue also highlights the need for robust mobile device management policies and security awareness training for users. This vulnerability falls under the ATT&CK technique T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, emphasizing the need for comprehensive mobile security controls and regular vulnerability assessments.