CVE-2022-22762 in Firefox
Summary
by MITRE • 12/22/2022
Under certain circumstances, a JavaScript alert (or prompt) could have been shown while another website was displayed underneath it. This could have been abused to trick the user. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 97.
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Analysis
by VulDB Data Team • 05/09/2026
This vulnerability represents a critical user interface security flaw in Firefox for Android that could enable sophisticated social engineering attacks through improper modal dialog handling. The issue stems from a race condition or timing flaw in the browser's JavaScript execution environment where alert and prompt dialogs could be displayed over content from different origins, creating a misleading user experience that violates fundamental security principles of browser isolation. The vulnerability specifically impacts Firefox versions prior to 97, with the Android mobile platform being the sole affected operating system, indicating a platform-specific implementation issue rather than a cross-platform problem. This flaw directly violates the principle of least privilege and user consent, as users might be tricked into interacting with malicious content that appears to be from a trusted source while actually being presented in a misleading context.
The technical implementation of this vulnerability involves the browser's handling of JavaScript modal dialogs within the Android WebView component, where the security boundaries between different web origins are not properly enforced during dialog presentation. This creates a scenario where a malicious website could potentially display an alert dialog that appears to originate from a legitimate site while the underlying content is actually from a different domain. The vulnerability can be categorized under CWE-691 as an insufficient control of a resource through time, specifically involving the improper handling of user interface elements across security boundaries. The flaw represents a failure in the browser's sandboxing mechanisms and could potentially be exploited to bypass user consent mechanisms or manipulate user interactions through deceptive presentation techniques.
The operational impact of this vulnerability extends beyond simple phishing attacks to encompass more sophisticated attack vectors including credential harvesting, unauthorized transaction confirmation, and manipulation of user decision-making processes. Attackers could craft malicious web pages that display misleading alerts while maintaining control over the underlying content, potentially tricking users into providing sensitive information or performing unintended actions. The Android-specific nature of this vulnerability suggests it may be related to how the WebView component handles JavaScript execution contexts or how the operating system's window management interacts with browser security models. This creates a unique threat landscape where mobile users are particularly vulnerable due to the increased reliance on mobile browsers for sensitive activities and the limited security controls available on mobile platforms.
Security mitigations for this vulnerability should include immediate patching of Firefox versions prior to 97, with particular attention to the Android platform-specific fixes. Organizations should implement browser hardening policies that enforce the latest security updates and consider deploying additional monitoring for suspicious JavaScript behavior patterns. The fix likely involves implementing stricter enforcement of origin-based security boundaries during modal dialog presentation, ensuring that JavaScript alerts and prompts can only be displayed in contexts that properly respect the security model. This vulnerability also highlights the importance of comprehensive mobile browser security testing and the need for robust cross-platform security validation. Network security teams should monitor for indicators of compromise related to malicious websites attempting to exploit this specific vulnerability, particularly in mobile environments where users may be less aware of browser security mechanisms and more susceptible to deceptive user interface elements. The ATT&CK framework would categorize this under T1566 for social engineering techniques and potentially T1059 for JavaScript-based execution methods, emphasizing the need for both defensive and detection capabilities to address this user interface security weakness.