CVE-2017-5458 in Firefox
Summary
by MITRE
When a "javascript:" URL is drag and dropped by a user into the addressbar, the URL will be processed and executed. This allows for users to be socially engineered to execute an XSS attack on themselves. This vulnerability affects Firefox < 53.
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Analysis
by VulDB Data Team • 08/27/2024
This vulnerability represents a critical cross-site scripting flaw that exploits user interaction patterns within the Firefox browser. The issue arises from the browser's handling of javascript URLs when they are dragged and dropped into the address bar, creating an unexpected execution path that bypasses normal security restrictions. The vulnerability specifically affects Firefox versions prior to 53, where the browser fails to properly sanitize or validate javascript URLs during this particular user interaction scenario. This behavior creates a significant attack surface where malicious actors can craft deceptive drag and drop operations to execute arbitrary javascript code within the user's browsing context, effectively enabling self-xss attacks through social engineering techniques.
The technical implementation of this vulnerability stems from Firefox's inadequate input validation mechanisms when processing javascript URLs through the address bar drag and drop functionality. When a user drags a javascript: URL and drops it into the address bar, the browser's URL processing pipeline fails to properly distinguish between legitimate navigation URLs and potentially malicious javascript code. This flaw operates at the application layer and represents a classic case of insufficient input sanitization, which aligns with CWE-79 - Cross-site Scripting. The vulnerability demonstrates how user interaction patterns can be exploited to circumvent security controls that normally protect against such attacks, creating an environment where users themselves become vectors for executing malicious code.
The operational impact of this vulnerability extends beyond simple code execution to encompass sophisticated social engineering attacks that can compromise user sessions and data. Attackers can craft malicious javascript URLs that appear benign when dragged into the address bar, fooling users into inadvertently executing code that can steal session cookies, redirect to malicious sites, or perform other harmful actions. This vulnerability enables attackers to bypass traditional browser security measures such as content security policies and same-origin restrictions, as the execution occurs within the context of the user's own browser session. The attack requires minimal technical sophistication from the attacker while potentially causing significant damage to user security and privacy.
Mitigation strategies for this vulnerability should focus on both immediate browser updates and user education. Organizations must ensure that all Firefox installations are updated to version 53 or later, where the vulnerability has been patched through improved URL validation and sanitization. The fix implemented by Mozilla addresses the core issue by strengthening input validation for javascript URLs during address bar processing, preventing automatic execution of potentially malicious code. Additionally, security awareness training should emphasize the dangers of drag and drop operations with unknown URLs, as well as the importance of verifying URL content before interacting with them. From an ATT&CK framework perspective, this vulnerability maps to techniques involving social engineering and user execution, specifically targeting the T1059.007 - Command and Scripting Interpreter: JavaScript sub-technique, and represents a critical weakness in the user interaction security model that requires both technical fixes and behavioral interventions to fully address.