CVE-2007-5459 in MouseoverDictionary
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the sidebar HTML page in the MouseoverDictionary before 0.6.2 extension for Mozilla Firefox allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 09/10/2018
The CVE-2007-5459 vulnerability represents a critical cross-site scripting flaw within the MouseoverDictionary Firefox extension version 0.6.1 and earlier. This security weakness resides in the sidebar HTML page implementation, creating a pathway for remote attackers to execute malicious code through web scripts or HTML injection techniques. The vulnerability specifically targets the extension's user interface component that displays dictionary definitions when users hover over text elements, making it particularly dangerous as it operates within the context of legitimate browser functionality.
The technical flaw stems from inadequate input validation and output encoding mechanisms within the extension's sidebar functionality. When users interact with the mouseover dictionary feature, the extension processes and displays dictionary entries without properly sanitizing user-supplied data or ensuring proper HTML escaping. This allows attackers to craft malicious input that gets rendered as executable code within the browser context, bypassing standard security boundaries. The unspecified vectors suggest that multiple injection points may exist within the extension's processing logic, potentially including dictionary lookup parameters, user-defined terms, or configuration data.
From an operational impact perspective, this vulnerability enables attackers to execute arbitrary code in the context of the victim's browser session, potentially leading to session hijacking, data theft, or further exploitation of the compromised system. The attack surface is particularly concerning because the extension operates within the Firefox browser environment, giving attackers access to cookies, local storage, and potentially sensitive information that users may have entered on web pages. The vulnerability undermines the security model of the browser extension architecture, allowing malicious actors to leverage legitimate extension functionality for nefarious purposes.
Mitigation strategies should focus on immediate patching to version 0.6.2 or later, which addresses the input validation deficiencies. Organizations should also implement browser security policies including content security policy headers, regular security assessments of browser extensions, and user education about extension security risks. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a typical ATT&CK technique under T1059 for executing malicious code through web-based attack vectors. Security professionals should consider implementing extension whitelisting policies and regular vulnerability scanning of browser extensions to prevent similar issues in the future.