MobSF Stored Cross-Site Scripting (XSS)

Overview

Product: MobSF Version: < 4.3.1 CWE-ID: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CVSS vector v.4.0: 8.5 (AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N) CVSS vector v.3.1: 8.1 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N) Description: Stored XSS in the iOS Dynamic Analyzer functionality. Impact: Leveraging this vulnerability would enable performing actions as users, including administrative users. Vulnerable component: dynamic_analysis.html https://github.com/MobSF/Mobile-Security-Framework-MobSF/blob/d1d3b7a9aeb1a8c8c7c229a3455b19ade9fa8fe0/mobsf/templates/dynamic_analysis/ios/dynamic_analysis.html#L406 Exploitation conditions: A malicious application was uploaded to the Correlium. Mitigation: Use escapeHtml() function on the bundle variable. Researcher: Oleg Surnin (Positive Technologies)

Research

Researcher discovered zero-day vulnerability Stored Cross-site Scripting (XSS) in MobSF in iOS Dynamic Analyzer functionality. According to Apple's documentation for bundle ID's, it must contain only alphanumeric characters (A–Z, a–z, and 0–9), hyphens (-), and periods (.). (https://developer.apple.com/documentation/bundleresources/information-property-list/cfbundleidentifier) However, an attacker can manually modify this value in Info.plist file and add special characters to the <key>CFBundleIdentifier</key> value. In the dynamic_analysis.html file you do not sanitize received bundle value from Corellium https://github.com/MobSF/Mobile-Security-Framework-MobSF/blob/d1d3b7a9aeb1a8c8c7c229a3455b19ade9fa8fe0/mobsf/templates/dynamic_analysis/ios/dynamic_analysis.html#L406

<img width="1581" alt="image" src="https://github.com/user-attachments/assets/8400f872-46c0-406c-9dd6-97655e499b75" />

Figure 1. Unsanitized bundle

As a result, it is possible to break the HTML context and achieve Stored XSS.

Vulnerability reproduction

To reproduce the vulnerability, follow the steps described below.

• Unzip the IPA file of any iOS application. Listing 1. Unzipping the file

unzip test.ipa

• Modify the value of <key>CFBundleIdentifier</key> by adding restricted characters in the Info.plist file.

<img width="560" alt="image-1" src="https://github.com/user-attachments/assets/3eedf216-45ab-4d73-9815-6b02827d36d4" />

Figure 2. Example of the modified Bundle Identifier

• Zip the modified IPA file.

Listing 2. Zipping the file

zip -r xss.ipa Payload/

• Upload the modified IPA file to your virtual device using the Correlium platform.

<img width="762" alt="image-2" src="https://github.com/user-attachments/assets/7f3e8b0d-d1f9-4d86-b63b-9b3f9e8f1d0c" />

Figure 3. Example of the uploaded malicious application

• Open the XSS functionality and hover the mouse over the Uninstall button of the malicious app.

<img width="764" alt="image-3" src="https://github.com/user-attachments/assets/fd621574-f2c1-42be-b30a-e8e7445c6b13" />

Figure 4. Example of the 'Uninstall' button

<img width="652" alt="image-4" src="https://github.com/user-attachments/assets/73526f71-6d39-4a94-98bf-8a867aa9acc7" />

Figure 5. Example of the XSS

<img width="460" alt="image-5" src="https://github.com/user-attachments/assets/13e6a1fc-59be-492d-8e42-a5a8010fc4c3" />

Figure 6. Example of the vulnerable code

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Please, assign all credits to: Oleg Surnin (Positive Technologies)

Affected packages

• mobsf < 4.3.1

Remediation

Upgrade to a patched release:

• mobsf 4.3.1