CVE-2012-1420 in F-Prot
Summary
by MITRE
The TAR file parser in Quick Heal (aka Cat QuickHeal) 11.00, Command Antivirus 5.2.11.5, F-Prot Antivirus 4.6.2.117, Fortinet Antivirus 4.2.254.0, K7 AntiVirus 9.77.3565, Kaspersky Anti-Virus 7.0.0.125, Antimalware Engine 1.1.6402.0 in Microsoft Security Essentials 2.0, NOD32 Antivirus 5795, Norman Antivirus 6.06.12, Panda Antivirus 10.0.2.7, and Rising Antivirus 22.83.00.03 allows remote attackers to bypass malware detection via a POSIX TAR file with an initial \7fELF character sequence. NOTE: this may later be SPLIT into multiple CVEs if additional information is published showing that the error occurred independently in different TAR parser implementations.
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Analysis
by VulDB Data Team • 05/04/2017
The vulnerability described in CVE-2012-1420 represents a significant weakness in multiple antivirus products' handling of TAR archive files, specifically targeting their file format parsers. This issue affects a wide range of security solutions including Quick Heal, Command Antivirus, F-Prot, Fortinet, K7 AntiVirus, Kaspersky, Microsoft Security Essentials, NOD32, Norman, Panda, and Rising antivirus platforms. The flaw manifests when these security applications encounter a specially crafted POSIX TAR file that begins with the sequence \7fELF characters, which are typically associated with executable binary files rather than archive formats.
The technical root cause of this vulnerability lies in the improper validation and parsing logic within these antivirus applications' TAR file handlers. When processing archive files, these products should correctly identify file types based on their headers and structure, but in this case, the presence of the \7fELF sequence causes the parsers to misinterpret the file type. This misinterpretation leads to a bypass of the malware detection mechanisms, as the system fails to properly analyze the contents of the archive. The vulnerability demonstrates a classic case of insufficient input validation and inadequate file type recognition, which are common patterns that fall under CWE-20, "Improper Input Validation," and CWE-470, "Use of Externally-Controlled Input to Select Case of a Switch Statement."
The operational impact of this vulnerability is substantial as it allows remote attackers to potentially deliver malware payloads that would otherwise be detected by these security solutions. Attackers can exploit this weakness by embedding malicious code within TAR archives that contain the problematic \7fELF character sequence, enabling them to evade detection and compromise systems. This bypass capability undermines the fundamental purpose of antivirus software, which is to identify and neutralize threats before they can cause damage. The vulnerability creates a persistent security gap that affects multiple vendors simultaneously, suggesting either a common code base or similar implementation flaws across these security products.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.007, "Command and Scripting Interpreter: PowerShell," and T1204.002, "User Execution: Malicious File," as it enables attackers to execute malicious payloads through seemingly benign archive files. The attack surface extends beyond simple file execution to include potential privilege escalation and lateral movement within compromised networks. Organizations using affected antivirus solutions face a critical risk where legitimate security controls become ineffective against specific attack vectors. The vulnerability's potential for being split into multiple CVEs indicates that similar issues may exist in other antivirus implementations, highlighting the need for comprehensive code review and security testing across the antivirus industry.
Mitigation strategies should include immediate updates to affected antivirus versions, implementation of network-based detection measures, and enhanced monitoring for suspicious archive file handling activities. Security teams must also consider deploying additional layers of protection such as application whitelisting, network segmentation, and behavioral analysis tools to compensate for the temporary loss of detection capability. Organizations should conduct thorough vulnerability assessments to identify other potential similar weaknesses in their security infrastructure and establish more robust file type identification mechanisms that can properly handle edge cases in file format parsing.