CVE-2009-4127 in Wikipedia Toolbar
Summary
by MITRE
Unspecified vulnerability in Wikipedia Toolbar extension before 0.5.9.2 for Firefox allows user-assisted remote attackers to execute arbitrary JavaScript with Chrome privileges via vectors involving unspecified Toolbar buttons and the eval function. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 12/21/2017
The vulnerability described in CVE-2009-4127 represents a critical security flaw within the Wikipedia Toolbar extension for Firefox browsers, specifically affecting versions prior to 0.5.9.2. This issue falls under the category of privilege escalation and code execution vulnerabilities that can have severe implications for user security and system integrity. The vulnerability's classification aligns with CWE-94, which deals with "Improper Control of Generation of Code ('Code Injection')" and CWE-79, "Cross-site Scripting (XSS)" as it involves the execution of arbitrary JavaScript code with elevated privileges. The Wikipedia Toolbar extension, designed to enhance user experience by providing quick access to Wikipedia content directly within the Firefox browser, inadvertently created a security vector that could be exploited by malicious actors.
The technical mechanism of exploitation involves the manipulation of Toolbar buttons and the deliberate use of the eval function within the browser environment. This particular vulnerability demonstrates how browser extensions can create dangerous attack surfaces when they improperly handle user input or fail to validate the execution context of code. The eval function, when used inappropriately, can transform user-controlled input into executable code, particularly when combined with the privileged context that browser extensions operating with chrome privileges can access. The attack requires user assistance, meaning that an attacker would need to convince a user to interact with a maliciously crafted page or element that triggers the vulnerable code path through the Toolbar buttons. This user-assisted nature does not diminish the severity, as social engineering remains a prevalent attack vector in modern cybersecurity.
The operational impact of this vulnerability extends beyond simple code execution, as it allows attackers to potentially access sensitive user data, manipulate browser behavior, and establish persistent access to compromised systems. When an extension operates with chrome privileges, it can access the same resources and permissions as the browser itself, creating a significant security risk. The exploitation could enable attackers to steal cookies, modify browser settings, inject malicious content into web pages, or even establish backdoors for further compromise. This vulnerability directly relates to ATT&CK technique T1176, "Browser Extensions"), which describes how attackers can leverage browser extensions to maintain persistence and execute malicious code within the browser environment. The fact that the vulnerability affects a widely used tool like Wikipedia Toolbar increases its potential impact, as users are more likely to trust and interact with familiar extensions.
Mitigation strategies for this vulnerability should focus on immediate patching and updating of the Wikipedia Toolbar extension to version 0.5.9.2 or later, which would presumably address the code injection vector through proper input validation and privilege management. Organizations and individuals should implement comprehensive browser extension management policies, regularly auditing installed extensions and ensuring they are from trusted sources. The broader cybersecurity community should consider implementing sandboxing techniques for browser extensions and enforcing stricter privilege models that prevent extensions from accessing chrome-level APIs without explicit user consent. Additionally, security awareness training should emphasize the risks associated with interacting with unfamiliar web content that might trigger browser extension vulnerabilities, as the user-assisted nature of this exploit relies heavily on social engineering tactics. The vulnerability also highlights the importance of proper code review processes for browser extensions, particularly in how they handle dynamic code execution and user input validation.