CVE-2005-3377 in Internet Security Suite
Summary
by MITRE
Multiple interpretation error in (1) McAfee Internet Security Suite 7.1.5 version 9.1.08 with the 4.4.00 engine and (2) McAfee Corporate 8.0.0 patch 10 with the 4400 engine allows remote attackers to bypass virus scanning via a file such as BAT, HTML, and EML with an "MZ" magic byte sequence which is normally associated with EXE, which causes the file to be treated as a safe type that could still be executed as a dangerous file type by applications on the end system, as demonstrated by a "triple headed" program that contains EXE, EML, and HTML content, aka the "magic byte bug."
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Analysis
by VulDB Data Team • 07/27/2017
The CVE-2005-3377 vulnerability represents a critical file type interpretation flaw in McAfee security products that fundamentally undermines the integrity of virus scanning mechanisms. This vulnerability affects specific versions of McAfee Internet Security Suite 7.1.5 with engine version 9.1.08 and McAfee Corporate 8.0.0 patch 10 with engine 4400, creating a dangerous misclassification scenario where malicious files can evade detection. The core technical issue stems from how these security applications interpret file headers, specifically the MZ magic byte sequence that traditionally identifies executable files. When files containing this sequence are processed, the security software incorrectly categorizes them as safe file types rather than potentially malicious executables, allowing the malware to bypass critical scanning mechanisms.
The operational impact of this vulnerability extends beyond simple bypass of antivirus detection, creating a sophisticated attack vector that leverages the principle of file type confusion. Attackers can craft "triple headed" programs that combine multiple file types within a single payload, using the MZ magic byte to disguise malicious content as legitimate files. This technique allows attackers to exploit the trust relationships between applications and file handlers, as the system treats these files as safe due to their apparent file type signatures while still maintaining executable capabilities. The vulnerability specifically targets the file type recognition algorithms within the antivirus engines, causing them to misinterpret the actual threat level of files that contain executable code disguised within seemingly benign file formats such as BAT, HTML, and EML files.
This security flaw directly relates to CWE-20, which addresses improper input validation, and represents a classic case of insecure file type handling that enables privilege escalation through content manipulation. The vulnerability aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, as the malicious files can execute commands through legitimate system interfaces. The attack surface is particularly concerning because it operates at the file system level where applications process files without proper security context validation, allowing the execution of malicious code through trusted file handlers. Organizations using affected McAfee versions face significant risk as this vulnerability enables attackers to bypass multiple layers of security controls that should prevent execution of malicious payloads.
The mitigation strategy for CVE-2005-3377 requires immediate patching of affected McAfee products to ensure proper file type recognition and validation. System administrators should implement additional file type validation controls at network boundaries and application level to detect and quarantine suspicious file combinations. The vulnerability highlights the importance of robust input validation and proper file type identification mechanisms within security software, emphasizing the need for comprehensive testing of file handling functions. Organizations should also consider implementing behavioral monitoring systems that can detect anomalous file execution patterns regardless of file type signatures, as this vulnerability demonstrates how traditional signature-based detection can be circumvented through clever manipulation of file headers. Regular security assessments of antivirus and endpoint protection systems are essential to identify similar interpretation flaws that could enable similar bypass techniques.