CVE-2005-3006 in Web Browser
Summary
by MITRE
The mail client in Opera before 8.50 opens attached files from the user s cache directory without warning the user, which might allow remote attackers to inject arbitrary web script and spoof attachment filenames.
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Analysis
by VulDB Data Team • 07/06/2021
The vulnerability described in CVE-2005-3006 represents a critical security flaw in Opera's email client implementation that existed prior to version 8.50. This issue stems from improper handling of cached email attachments, creating a significant attack vector for remote adversaries seeking to compromise user systems. The vulnerability specifically affects the mail client component of the Opera browser suite, which was widely used during that period as both a web browser and email client. The flaw demonstrates a fundamental failure in input validation and user interface security design, where the application automatically processes cached files without proper user awareness or consent mechanisms.
The technical implementation of this vulnerability allows attackers to exploit the lack of proper file validation when processing email attachments stored in the user's cache directory. When users receive email messages containing malicious attachments, the Opera mail client retrieves these files from the cache without displaying appropriate warnings or prompts to the user. This behavior creates an environment where attackers can craft malicious web scripts within attachment filenames or content that will execute automatically when the cached files are accessed. The vulnerability operates at the intersection of file system access controls and user interface security, where the application assumes that cached files are safe without verifying their integrity or origin. This flaw directly relates to CWE-22, which addresses improper limitation of a pathname to a restricted directory, and CWE-74, which covers injection flaws, particularly in the context of web script injection.
The operational impact of this vulnerability extends beyond simple script execution, as it enables sophisticated social engineering attacks that can deceive users into believing they are accessing legitimate files. Attackers can craft malicious filenames that appear benign while containing embedded web scripts that execute in the context of the user's browser session. The spoofing capability allows threat actors to manipulate how attachment names appear to users, making it difficult for individuals to distinguish between legitimate and malicious content. This vulnerability particularly affects users who rely on Opera's integrated email functionality, creating a persistent threat vector that could compromise entire user sessions. The attack surface is significant since it requires no user interaction beyond receiving the initial malicious email, making it an ideal vector for automated phishing campaigns and drive-by downloads.
Security professionals should implement immediate mitigations including updating to Opera version 8.50 or later, which addressed this vulnerability through enhanced file validation and user warning mechanisms. Organizations should also consider implementing email filtering solutions that can detect and quarantine suspicious attachment patterns, particularly those that might exploit this caching behavior. The vulnerability highlights the importance of proper input validation and user awareness in email client security, with recommendations aligning with ATT&CK technique T1566 for credential access through social engineering. Network administrators should monitor for unusual email traffic patterns and consider implementing sandboxing techniques for email attachments, while users should be educated about the risks of automatically opening cached email content and the importance of verifying attachment origins before interaction.