Document Title: =============== Fing v3.3.0 iOS - Persistent Mail Encoding Vulnerability Date: ===== 2016-02-28 References: =========== VL-ID: ===== 1772 Common Vulnerability Scoring System: ==================================== 3.5 Introduction: ============= Find out which devices are connected to your Wi-Fi network, in just a few seconds. Fast and accurate, Fing is a professional App for network analysis. A simple and intuitive interface helps you evaluate security levels, detect intruders and resolve network issues. Discovers all devices connected to a Wi-Fi network. Unlimited devices and unlimited networks, for free! (Copy of the Homepage: ) Abstract: ========= The Vulnerability Laboratory Core Research Team discovered an application-side mail encoding web vulnerability in the official Fing mobile iOS application. Report-Timeline: ================ 2016-02-29: Public Disclosure (Vulnerability Laboratory) Status: ======== Published Affected Products: ================== Exploitation-Technique: ======================= Local Severity: ========= Medium Details: ======== An application-side input validation web vulnerability has been discovered in the official Fing mobile iOS web-application. The security web vulnerability allows to inject malicious script codes on the application-side of the vulnerable iOS mobile app. The vulnerability is located in the encode mechanism of the `Address` input field. Local attackers with restricted or privileged web-application user accounts are able to inject the address input to the mail body message context on sharing. The attacker injects a new Hostname Address to scan and shares the input context mail mail to the addressbook. The injection point is the Address input field and the execution point is the mail message body context. The security risk of the application-side vulnerability is estimated as medium with a cvss (common vulnerability scoring system) count of 3.5. Exploitation of the persistent web vulnerability requires a low privileged ios device account with restricted access and low user interaction. Successful exploitation of the vulnerabilities results in persistent phishing mails, session hijacking, persistent external redirect to malicious sources and application-side manipulation of affected or connected module context. Vulnerable Module(s) [+] Edit Scan (Add Hostname) Vulnerable Input(s): [+] Address Vulnerable Parameter(s) [+] hostname Affected Module(s) [+] Mail Message Body (Share Function) Proof of Concept: ================= The application-side validation web vulnerability can be exploited by remote attackers with low privileged iOS device user account and without user interaction. For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue. Manual steps to reproduce the vulnerability ... 1. Install the Fing Scanner iOS app 2. Start the app 3. Click the second button in the bottom menu to edit a scan 4. Inject a script code payload to the "Address / Hostname" input field 5. Now click above the share button and choose send by email Note: The payload of the scan is not getting saved to the mail body message context 6. The execution occurs directly in the mail body of the email context 7. Successful reproduce of the vulnerability! PoC: Find (Send by Mail to Share)
Betreff: Fing discovery report for "><img>%20<iframe>%20<iframe src="x"> (No address)
Von: Benjamin Mejri Kunz <>
Datum: 28.02.2016 18:38

Host Name: ">%20

Von meinem iPad gesendet
Solution: ========= The vulnerability can be patched by a secure parse and encode of the vulnerable `Address/Hostname` input field. Restrict the input field and disallow usage of special chars. Encode the mail message body context that is getting transfered of the address input to the email body context. Risk: ===== The security risk of the persistent mail encoding web vulnerability in the fing scanner iOS app is estimated as medium. (CVSS 3.5) Credits: ======== Vulnerability Laboratory [Research Team] - Benjamin Kunz Mejri ( [] Disclaimer: =========== 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 licenses, policies, deface websites, hack into databases or trade with stolen data. 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, modify, use or edit our material contact (admin@ or to get a ask permission. Copyright © 2016 | Vulnerability Laboratory - [Evolution Security GmbH]™