CVE-2004-2083 in Web Browser
Summary
by MITRE
Opera Web Browser 7.0 through 7.23 allows remote attackers to trick users into executing a malicious file by embedding a CLSID in the file name, which causes the malicious file to appear as a trusted file type, aka "File Download Extension Spoofing."
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Analysis
by VulDB Data Team • 06/29/2021
The vulnerability identified as CVE-2004-2083 represents a significant security flaw in Opera web browser versions 7.0 through 7.23 that enables malicious actors to conduct deceptive file download operations. This issue falls under the category of extension spoofing attacks where attackers exploit the browser's file handling mechanisms to manipulate user perception of file types during download operations. The vulnerability specifically targets the browser's method of determining file extensions and associated trust levels, creating a pathway for social engineering attacks that can bypass user security awareness.
The technical implementation of this flaw involves embedding a Component Object Model Class Identifier or CLSID within the filename of a malicious file that is being downloaded from a remote server. When Opera processes such a file, it interprets the CLSID embedded within the filename and subsequently displays the file with a trusted extension or icon, even though the actual file content remains malicious. This manipulation occurs at the browser's file association and display layer, where the system incorrectly associates the malicious file with a trusted file type based on the embedded CLSID rather than examining the actual file content or extension. This behavior aligns with CWE-451, which addresses "Use of Untrusted Input in a Web Query" and represents a form of input validation weakness that allows attackers to manipulate the browser's interpretation of file types.
The operational impact of this vulnerability extends beyond simple deception to potentially enable more sophisticated attack vectors including malware installation, privilege escalation, and system compromise. Users who download files believing them to be legitimate due to the trusted appearance may unknowingly execute malicious code that takes advantage of the trust relationship established by the browser's display mechanism. The attack requires minimal technical expertise from the adversary and leverages the browser's trust model, making it particularly dangerous in environments where users may not be security-aware or where automated downloads occur. This vulnerability demonstrates the critical importance of proper input validation and the potential for seemingly minor implementation flaws to create significant security risks.
Security mitigations for CVE-2004-2083 should focus on updating to newer versions of Opera browser where this vulnerability has been addressed through improved file extension validation and enhanced security checks. Users should implement additional protective measures including browser security extensions, file type filtering, and user education about suspicious download behaviors. Organizations should consider implementing network-level controls to monitor and block suspicious file downloads, particularly those containing embedded CLSIDs or other potentially malicious indicators. The vulnerability also highlights the need for comprehensive security testing of browser components, particularly those involved in file handling and user interface presentation, as outlined in ATT&CK technique T1059.3 for Windows Scripting and T1070 for Indicator Removal on Host. System administrators should ensure that all browser installations are kept current with security patches and that appropriate security policies are enforced to prevent exploitation of such vulnerabilities.