CVE-2014-6392 in Facebook
Summary
by MITRE
** DISPUTED ** Cross-site scripting (XSS) vulnerability in the Facebook app 14.0 and the Facebook Messenger app 10.0 for iOS allows remote attackers to inject arbitrary web script or HTML via a crafted filename extension that is improperly handled during MIME sniffing of chat traffic. NOTE: the vendor disputes the significance of this report, because the user must accept an interstitial warning before the HTML file content is rendered, and because the HTML content s origin is a sandbox domain.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/06/2024
The vulnerability described in CVE-2014-6392 represents a cross-site scripting issue affecting Facebook's mobile applications, specifically version 14.0 of the Facebook app and version 10.0 of the Facebook Messenger app for iOS devices. This security flaw resides in the applications' handling of file content during MIME type detection processes within chat traffic. The vulnerability occurs when a malicious actor crafts a filename extension that triggers improper MIME sniffing behavior, allowing arbitrary web script or HTML code to be injected into the application's rendering environment. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications and mobile platforms.
The technical exploitation of this vulnerability requires a sophisticated attack vector that leverages the improper handling of file content during the MIME detection phase of chat message processing. When a user receives a maliciously crafted file with a specially constructed filename extension, the application's MIME sniffing mechanism fails to properly validate or sanitize the content before rendering. This creates an environment where malicious HTML content can be executed within the application context, potentially allowing attackers to perform actions such as stealing session cookies, redirecting users to malicious sites, or executing unauthorized commands within the application's sandboxed environment. The attack scenario requires user interaction through accepting an interstitial warning, which adds a layer of complexity to the exploitation process but does not eliminate the security risk entirely.
The operational impact of this vulnerability extends beyond simple script execution, as it represents a potential pathway for more sophisticated attacks within the Facebook ecosystem. Mobile application security is particularly critical given the sensitive nature of user communications and personal data stored within these platforms. The fact that the HTML content originates from a sandbox domain does not completely mitigate the risk, as attackers could potentially leverage this vulnerability to escalate privileges or access additional system resources. The vendor's position that this issue is not significant due to the interstitial warning mechanism reflects a common debate in security circles about the effectiveness of user warnings versus inherent application vulnerabilities. However, user warnings can be bypassed or ignored, particularly when users are not properly educated about security risks.
Security professionals should consider this vulnerability in the context of broader mobile application security frameworks and the ATT&CK framework's mobile application categories. The vulnerability demonstrates the importance of proper input validation and content sanitization even in sandboxed environments where traditional security boundaries may not apply. Organizations should implement comprehensive mobile security monitoring that includes behavioral analysis of application interactions, particularly around file handling and content rendering processes. The remediation approach should focus on strengthening MIME type detection mechanisms, implementing more robust content validation before rendering, and potentially removing or limiting automatic content rendering of potentially malicious file types. Additionally, user education about the risks of accepting unknown file types and the importance of security warnings remains crucial in defending against such vulnerabilities.
The disputed nature of this vulnerability by the vendor highlights the complexity of security assessments in mobile applications where multiple security controls and user interactions must be considered. While the vendor argues that the interstitial warning provides sufficient protection, security experts recognize that such controls are not foolproof and can be circumvented through social engineering or user complacency. This case demonstrates the ongoing challenge in mobile security where applications must balance user experience with comprehensive security controls, particularly in environments where users may not fully understand the implications of accepting potentially malicious content. The vulnerability serves as a reminder that even sandboxed applications require rigorous security testing and validation of all content handling processes to prevent potential exploitation through sophisticated attack vectors.