CVE-2008-5542 in VIPRE
Summary
by MITRE
Sunbelt VIPRE 3.1.1832.2 and possibly 3.1.1633.1, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.
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Analysis
by VulDB Data Team • 10/22/2018
The vulnerability described in CVE-2008-5542 represents a significant bypass mechanism within Sunbelt VIPRE antivirus software version 3.1.1832.2 and potentially earlier versions 3.1.1633.1. This flaw specifically affects the software's behavior when Internet Explorer 6 or 7 is utilized as the browser environment, creating a critical gap in malware detection capabilities. The vulnerability stems from the antivirus solution's insufficient file type analysis and content inspection mechanisms, allowing malicious actors to craft HTML documents that evade traditional detection methods by exploiting the software's handling of file extensions and binary headers.
The technical exploitation of this vulnerability relies on the manipulation of file headers and extensions to deceive the antivirus engine's heuristic analysis. By placing an MZ header - which is the standard signature for windows executable files - at the beginning of an HTML document, attackers can effectively disguise malicious payloads within seemingly benign web content. This technique specifically targets the filename extension handling logic within VIPRE's detection algorithms, where the software fails to properly analyze the actual file content when presented with filenames lacking extensions or with extensions that do not match the underlying file type. The vulnerability operates under the principle of file extension manipulation and header deception, which are common attack vectors that have been documented in various cybersecurity frameworks.
The operational impact of this vulnerability extends beyond simple malware evasion to represent a fundamental flaw in the antivirus software's content analysis methodology. When an HTML document containing a malicious payload is served to a user with Internet Explorer 6 or 7, the antivirus system incorrectly classifies the document as safe due to its improper handling of the file's binary signature and extension mismatch. This creates a false sense of security for users who may unknowingly execute malicious code that would normally be detected by proper antivirus scanning. The vulnerability particularly affects systems where users are browsing the internet and encountering web-based attacks, making it a significant concern for enterprise environments and individual users who rely on the software for protection against web-based threats. The issue has been demonstrated using CVE-2006-5745 as an exploit, which further illustrates the severity of the vulnerability and its potential for delivering sophisticated malware.
The root cause of this vulnerability aligns with CWE-20, which describes improper input validation, and CWE-427, which addresses uncontrolled search path elements. The antivirus software fails to properly validate file content against its actual binary signature rather than relying solely on filename extensions, creating a path for attackers to manipulate the detection process. From an attack perspective, this vulnerability maps to techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1203 for exploitation for client execution, as it enables attackers to bypass security controls and execute malicious code through web browsers. The vulnerability's exploitation requires minimal technical expertise and can be automated, making it particularly dangerous for widespread deployment. Organizations should implement immediate mitigations including updating to patched versions of VIPRE software, implementing additional network-based security controls, and educating users about the risks of opening suspicious web content. The vulnerability also highlights the importance of comprehensive file analysis that goes beyond simple extension-based detection and includes thorough content inspection and binary signature verification to prevent similar bypass techniques from succeeding.