CVE-2004-2442 in F-Secure
Summary
by MITRE
Multiple interpretation error in various F-Secure Anti-Virus products, including Workstation 5.43 and earlier, Windows Servers 5.50 and earlier, MIMEsweeper 5.50 and earlier, Anti-Virus for Linux Servers and Gateways 4.61 and earlier, and other products, allows remote attackers to bypass antivirus protection via a compressed file with both local and global headers set to zero, which does not prevent the compressed file from being opened on the target system.
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Analysis
by VulDB Data Team • 11/21/2024
This vulnerability represents a critical flaw in multiple F-Secure anti-virus products that stems from improper handling of compressed file structures during virus scanning operations. The issue manifests when compressed files contain both local and global headers set to zero, creating a condition where the anti-virus software fails to properly interpret the file structure and subsequently allows the malicious payload to bypass protection mechanisms. This interpretation error occurs at the core of the decompression and analysis processes within the anti-virus engines, fundamentally undermining the security posture of affected systems.
The technical root cause of this vulnerability lies in the insufficient validation of compressed file metadata within the F-Secure scanning engines. When processing compressed archives, the software fails to properly validate header values and their relationships, allowing specially crafted malicious files to exploit this weakness. The zero-valued headers create ambiguity in the parsing logic, causing the anti-virus system to either skip critical validation steps or misinterpret the file structure entirely. This weakness aligns with CWE-129, which addresses improper validation of input boundaries, and CWE-248, concerning exposure of a uninitialized variable. The flaw essentially creates a path where compressed files can be processed without proper security checks, enabling attackers to deliver malware through seemingly benign compressed archives.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on F-Secure products for endpoint and server protection. Remote attackers can exploit this weakness by crafting malicious compressed files that appear legitimate to the anti-virus system while containing actual malicious content. The attack vector is particularly dangerous because it leverages the very functionality that anti-virus software is designed to protect against, essentially allowing malware to bypass protection through legitimate file processing mechanisms. This vulnerability directly impacts the core security promise of anti-virus solutions and can lead to complete system compromise when successful attacks occur. The risk is compounded by the fact that this affects multiple product lines including workstation, server, and Linux-based solutions, suggesting a systemic flaw in the underlying scanning architecture.
The implications of this vulnerability extend beyond simple bypass of anti-virus protection, as it represents a fundamental failure in the security validation process that could potentially enable more sophisticated attack patterns. Organizations may experience unauthorized access, data exfiltration, or system compromise when this vulnerability is exploited, particularly in environments where compressed files are commonly processed. The attack can be executed remotely without requiring user interaction or specialized privileges, making it particularly dangerous in enterprise environments. According to ATT&CK framework, this vulnerability maps to technique T1059.007 for command and scripting interpreter, and T1204.002 for user execution, as it enables the execution of malicious code through seemingly legitimate file operations. Organizations should consider this vulnerability as a potential entry point for broader attack campaigns, as it undermines the trust model that anti-virus systems provide.
Mitigation strategies should focus on immediate patching of affected F-Secure products, as well as implementing additional network-level controls to monitor and restrict execution of compressed files from untrusted sources. Organizations should also consider deploying additional security layers including network firewalls, intrusion detection systems, and behavioral monitoring tools to detect anomalous file processing patterns. The vulnerability highlights the importance of proper input validation and the need for comprehensive testing of file parsing logic in security software. Regular security assessments should include testing for similar interpretation errors in other anti-virus and security products, as this type of vulnerability can often be found in complex file processing systems. Additionally, organizations should implement strict file type controls and maintain up-to-date threat intelligence to detect and block known malicious compressed file patterns.