CVE-2019-11698 in Firefox
Summary
by MITRE
If a crafted hyperlink is dragged and dropped to the bookmark bar or sidebar and the resulting bookmark is subsequently dragged and dropped into the web content area, an arbitrary query of a user's browser history can be run and transmitted to the content page via drop event data. This allows for the theft of browser history by a malicious site. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.
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Analysis
by VulDB Data Team • 11/26/2025
This vulnerability represents a sophisticated cross-site scripting attack vector that exploits the browser's handling of drag and drop operations combined with bookmark management. The flaw resides in how browsers process user-generated content through the bookmark system, specifically when crafted hyperlinks are manipulated through drag and drop interactions. The vulnerability operates at the intersection of web security boundaries where user input should be sanitized but isn't properly validated during the bookmark creation and subsequent drop event processing phases.
The technical implementation of this exploit leverages the browser's bookmark bar and sidebar functionality to create a malicious bookmark that, when dropped into web content areas, triggers a drop event containing browser history data. This occurs because the browser fails to properly sanitize the bookmark data before allowing it to interact with web content through the drop event mechanism. The vulnerability stems from improper input validation and insufficient sandboxing between user interface components and web content execution contexts.
The operational impact of this vulnerability is significant as it enables malicious websites to harvest sensitive user browsing history without user consent or awareness. Attackers can craft malicious links that, when interacted with through the drag and drop interface, silently extract browsing patterns and potentially sensitive information. This creates a persistent threat vector that can be exploited across multiple browser sessions and potentially across different domains, as demonstrated by the affected software versions including Thunderbird 60.6 and Firefox versions prior to 67. The vulnerability essentially bypasses standard browser security models by exploiting legitimate user interface interactions to create an information leakage channel.
Security mitigations for this vulnerability include immediate software updates to patched versions of affected browsers and email clients, as well as implementing stricter content security policies that prevent unauthorized access to browser history through drop events. Organizations should also consider deploying web application firewalls that can detect and block suspicious drag and drop operations involving bookmark data. The fix typically involves implementing proper sanitization of bookmark data during drop operations and ensuring that browser history information cannot be accessed through user interface events that are meant for legitimate content interaction. This vulnerability aligns with CWE-79 Cross-site Scripting and ATT&CK techniques related to credential access and information gathering through browser-based attacks.
The vulnerability demonstrates the complexity of modern browser security where legitimate user interface features can become attack vectors when not properly secured against malicious input. It highlights the importance of comprehensive security testing that includes user interaction scenarios and the need for proper input validation at all levels of the browser stack. The affected software versions represent a critical security gap that required immediate patching to prevent widespread exploitation and potential privacy breaches for users who interacted with malicious content through standard browser operations.