CVE-2005-3218 in Dr.Web
Summary
by MITRE
Multiple interpretation error in unspecified versions of Dr.Web Antivirus allows remote attackers to bypass virus detection via a malicious executable in a specially crafted RAR file with malformed central and local headers, which can still be opened by products such as Winrar and PowerZip, even though they are rejected as corrupted by Winzip and BitZipper.
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Analysis
by VulDB Data Team • 07/27/2017
The vulnerability described in CVE-2005-3218 represents a critical flaw in Dr.Web Antivirus software that demonstrates the complex challenges of malware detection and file format parsing in antivirus systems. This issue stems from multiple interpretation errors within the antivirus engine's handling of RAR archive files, specifically when these archives contain malicious executables embedded within specially crafted archive structures. The vulnerability exploits inconsistencies in how different archive utilities process malformed file headers, creating a scenario where certain archive viewers can successfully open files while others reject them as corrupted. The flaw exists in the way Dr.Web interprets the central and local headers of RAR files, which are fundamental components of the RAR compression format that define file locations, sizes, and metadata within the archive structure.
The technical implementation of this vulnerability involves the manipulation of RAR file header structures to create archives that appear valid to some archive utilities while remaining detectable by others. When Dr.Web Antivirus encounters such a malformed RAR file, its parsing logic fails to correctly identify the malicious payload contained within the archive, allowing the malware to bypass detection mechanisms. This type of error falls under the category of parsing errors and improper input validation, which are commonly classified as CWE-129 Input Validation and CWE-125 Out-of-bounds Read in the Common Weakness Enumeration catalog. The vulnerability demonstrates how inconsistencies in file format interpretation can create security gaps, particularly when different software components handle the same data structures with varying degrees of strictness in their validation processes.
From an operational perspective, this vulnerability presents significant risks to organizations relying on Dr.Web Antivirus for protection against malware threats. Attackers can exploit this weakness by creating malicious RAR archives that will be accepted and opened by popular archive utilities like WinRAR and PowerZip while remaining undetected by Dr.Web's scanning mechanisms. This creates a false sense of security for users who may unknowingly execute malicious code contained within these archives, as the antivirus software fails to properly analyze the threat. The impact extends beyond simple malware execution, as the vulnerability could potentially be leveraged for more sophisticated attack vectors, including privilege escalation or lateral movement within compromised networks. The flaw essentially allows attackers to craft payloads that can evade detection by specific antivirus vendors, creating a targeted attack surface that exploits vendor-specific implementation differences in file format handling.
The mitigation strategies for this vulnerability require immediate patching of affected Dr.Web Antivirus versions and implementation of additional security controls to address the underlying parsing inconsistencies. Organizations should ensure that all antivirus software is updated to the latest versions that contain fixes for this specific vulnerability, as well as implement layered security approaches that include multiple detection mechanisms. Network administrators should consider implementing additional file validation measures, such as content inspection of archive files and behavioral monitoring of suspicious file execution patterns. The ATT&CK framework categorizes this type of vulnerability under T1059 Command and Scripting Interpreter and T1070 Indicator Removal on Host, as attackers can use such flaws to execute malicious code while avoiding detection. Regular security assessments and penetration testing should be conducted to identify similar parsing vulnerabilities in other security tools and systems, ensuring comprehensive protection against similar exploitation techniques that rely on inconsistent interpretation of file format structures.