CVE-2008-0318 in ClamAV
Summary
by MITRE
Integer overflow in the cli_scanpe function in libclamav in ClamAV before 0.92.1, as used in clamd, allows remote attackers to cause a denial of service and possibly execute arbitrary code via a crafted Petite packed PE file, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 07/25/2024
The vulnerability described in CVE-2008-0318 represents a critical integer overflow flaw within the ClamAV antivirus engine's libclamav library. This issue affects ClamAV versions prior to 0.92.1 and specifically impacts the cli_scanpe function responsible for scanning portable executable files. The vulnerability arises from improper handling of integer values during the processing of Petite packed PE files, which are commonly used by malware authors to obfuscate their malicious code. The flaw enables remote attackers to craft specially designed files that can trigger unexpected behavior in the antivirus scanning process.
The technical implementation of this vulnerability stems from an integer overflow condition that occurs when processing compressed or packed executable files. When the cli_scanpe function encounters a Petite packed PE file, it performs calculations that can exceed the maximum value that can be represented by the integer data type being used. This overflow condition leads to incorrect memory allocation decisions and subsequently causes a heap-based buffer overflow during the scanning process. The buffer overflow occurs because the system allocates insufficient memory space for the decompressed data, creating writable memory regions that can be overwritten with malicious content.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling remote code execution. Attackers can leverage this weakness by constructing malicious Petite packed PE files that, when scanned by vulnerable ClamAV installations, trigger the integer overflow and subsequent buffer overflow conditions. This creates a potential attack vector where remote adversaries can execute arbitrary code on systems running vulnerable ClamAV versions. The vulnerability is particularly concerning because it affects the core scanning functionality of ClamAV, meaning that any PE file processed by the antivirus engine could potentially be used to exploit this flaw, including files that are automatically scanned as part of routine system operations.
The security implications of CVE-2008-0318 align with common attack patterns documented in the MITRE ATT&CK framework, specifically relating to privilege escalation and execution through file processing. This vulnerability demonstrates the importance of input validation and proper integer handling in security software, as the flaw exists within the antivirus engine itself rather than in the scanned content. Organizations using ClamAV should prioritize immediate patching to address this vulnerability, as it represents a significant risk to system security and stability. The flaw also highlights the need for proper memory management practices and input sanitization in security tools to prevent exploitation of similar vulnerabilities in other antivirus and security software implementations.
This vulnerability serves as a prime example of how seemingly benign file processing operations can become attack vectors when proper input validation and memory management practices are not implemented. The integer overflow condition in cli_scanpe function demonstrates the critical nature of proper boundary checking in security software, as such flaws can be exploited to compromise the very systems designed to protect them. The remediation process requires updating to ClamAV version 0.92.1 or later, which includes proper integer overflow protections and improved memory handling for packed executable files. Organizations should also consider implementing additional security controls such as network segmentation and file access restrictions to limit potential exploitation of this vulnerability in environments where immediate patching may not be feasible.