CVE-2024-8382 in Firefox
Summary
by MITRE • 09/03/2024
Internal browser event interfaces were exposed to web content when privileged EventHandler listener callbacks ran for those events. Web content that tried to use those interfaces would not be able to use them with elevated privileges, but their presence would indicate certain browser features had been used, such as when a user opened the Dev Tools console. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 11/05/2025
This vulnerability represents a critical information disclosure issue in Mozilla Firefox browsers where internal browser event interfaces were inadvertently exposed to web content. The flaw occurred when privileged event handler listener callbacks executed for specific browser events, creating a scenario where web pages could access interfaces that should have remained restricted to browser internals. The vulnerability specifically affected Firefox versions prior to 130, Firefox ESR versions prior to 128.2, and Firefox ESR versions prior to 115.15, indicating a widespread impact across multiple browser channels and support releases.
The technical nature of this vulnerability stems from improper access control mechanisms within Firefox's event handling architecture. When privileged event handlers executed, they would expose internal interfaces to web content through the event object or related callback mechanisms. While these exposed interfaces could not be used with elevated privileges, their mere presence served as a fingerprinting mechanism that revealed browser internals to malicious web pages. This exposure created a covert channel through which attackers could determine whether specific browser features had been utilized, such as when users opened the Developer Tools console, which would manifest through the presence of these interfaces.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables sophisticated reconnaissance capabilities for attackers. Web content could leverage this exposure to perform browser fingerprinting, identifying whether users had accessed developer tools or other privileged browser features. This information could be used to build detailed user profiles, potentially enabling more targeted attacks or bypassing security measures that assume certain browser states. The vulnerability aligns with CWE-200 (Information Exposure) and represents a specific case of information leakage through improper access control. From an attacker's perspective, this could facilitate the identification of users who might be conducting security research or who have access to privileged browser features, potentially exposing them to targeted attacks.
Security practitioners should prioritize immediate remediation of this vulnerability by updating to affected Firefox versions. The fix addresses the underlying access control issue in Firefox's event handling system, ensuring that privileged interfaces remain properly isolated from web content. Organizations should implement comprehensive browser update policies and consider using automated patch management systems to ensure all Firefox installations remain current. Additionally, security monitoring should include detection of potential exploitation attempts through fingerprinting techniques that leverage this vulnerability, particularly in environments where browser-based attacks are a concern. The vulnerability demonstrates the importance of maintaining strict isolation between privileged browser components and web content, reinforcing principles from the ATT&CK framework related to privilege escalation and information gathering techniques.