CVE-2025-23108 in Firefox
Summary
by MITRE • 01/11/2025
Opening Javascript links in a new tab via long-press in the Firefox iOS client could result in a malicious script spoofing the URL of the new tab. This vulnerability was fixed in Firefox for iOS 134.
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Analysis
by VulDB Data Team • 04/15/2026
This vulnerability in the Firefox iOS client represents a sophisticated cross-site scripting attack vector that exploits user interaction patterns to deceive victims into believing they are visiting legitimate websites while actually executing malicious code. The flaw specifically manifests when users perform a long-press action on javascript links that initiate new tab openings, creating a critical security gap in the browser's URL validation and display mechanisms. The vulnerability stems from insufficient sanitization of javascript protocol links during tab creation processes, allowing attackers to craft deceptive URLs that appear legitimate while containing malicious payloads.
The technical implementation of this vulnerability involves the manipulation of the browser's tab opening behavior where javascript: protocol links are processed without proper validation of the script content. When a user long-presses on such a link, the browser creates a new tab but fails to properly isolate or sanitize the javascript execution context, enabling the malicious script to spoof the displayed URL while maintaining execution control over the new tab environment. This behavior creates a trust relationship between the user and the browser that is fundamentally compromised, as the URL bar display no longer accurately represents the actual content being executed. The vulnerability operates at the intersection of user interaction models and browser security boundaries, exploiting the expectation that tab URLs reflect actual destinations rather than deceptive script execution contexts.
The operational impact of this vulnerability extends beyond simple phishing attacks to encompass broader session hijacking and credential theft scenarios. Attackers can leverage this flaw to create convincing fake login pages or malicious file download prompts that appear to originate from legitimate domains, significantly increasing the success rate of social engineering campaigns. The vulnerability affects all users of Firefox iOS versions prior to 134, creating a widespread exposure that could be exploited across various threat actors including nation-state groups, cybercriminal organizations, and individual attackers. The attack vector is particularly dangerous because it requires minimal user interaction beyond the standard long-press gesture, making it difficult to defend against through traditional security awareness training alone.
Mitigation strategies should prioritize immediate patching of affected Firefox iOS versions to 134 or later, as this represents the primary defense against exploitation. Organizations should implement additional security controls including network-based filtering to block javascript: protocol links and browser security policies that restrict tab creation from external sources. The vulnerability aligns with attack patterns documented in the attack tree framework where users are manipulated through familiar interaction patterns to execute malicious code. Security teams should also consider implementing browser extension solutions that provide enhanced URL validation and tab security monitoring, particularly in enterprise environments where users may be exposed to higher-risk threat landscapes. This vulnerability demonstrates the critical importance of validating all user interaction contexts and maintaining strict separation between URL presentation and script execution environments as outlined in secure coding practices and defense-in-depth strategies.