CVE-2005-2720 in ViRobot Expert
Summary
by MITRE
Stack-based buffer overflow in the ACE archive decompression library (vrAZace.dll) in HAURI Anti-Virus products including ViRobot Expert 4.0, Advanced Server, Linux Server 2.0, and LiveCall, when compressed file scanning is enabled, allows remote attackers to execute arbitrary code via an ACE archive that contains a file with a long filename.
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Analysis
by VulDB Data Team • 06/12/2019
The vulnerability identified as CVE-2005-2720 represents a critical stack-based buffer overflow within the ACE archive decompression library component of HAURI Anti-Virus products. This flaw specifically affects multiple versions of the ViRobot Expert 4.0, Advanced Server, Linux Server 2.0, and LiveCall antivirus solutions, creating a significant security risk for organizations relying on these protection mechanisms. The vulnerability stems from inadequate input validation during the decompression process of ACE archive files, particularly when handling filenames that exceed predetermined buffer limits. The affected vrAZace.dll library demonstrates poor memory management practices that allow attackers to overwrite adjacent stack memory locations through carefully crafted malicious archive files. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is classified as a fundamental memory corruption flaw that has been consistently identified as one of the most dangerous security weaknesses in software systems. The attack vector is particularly concerning because it enables remote code execution without requiring local system access, making it an attractive target for cybercriminals seeking to compromise systems from external networks.
The technical implementation of this vulnerability occurs when the ACE archive decompression library processes compressed files containing excessively long filenames that exceed the allocated buffer space on the stack. During normal operation, the library allocates a fixed-size buffer to store filename information, but when an attacker crafts an ACE archive with a filename that surpasses this predetermined limit, the excess data overflows into adjacent memory locations. This overflow can overwrite return addresses, function pointers, and other critical stack data structures, potentially allowing an attacker to redirect program execution to malicious code. The vulnerability is particularly dangerous because it operates within the context of antivirus scanning functionality, which typically runs with elevated privileges to properly inspect and process potentially malicious files. When compressed file scanning is enabled, the system automatically invokes the vulnerable vrAZace.dll library, creating an automated attack surface that requires no user interaction to exploit. The nature of the buffer overflow means that attackers can manipulate the execution flow of the antivirus software itself, potentially leading to complete system compromise.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally undermines the security posture of systems running affected HAURI products. Organizations utilizing these antivirus solutions face the risk of unauthorized access, data breaches, and complete system compromise through this single vulnerability. The fact that multiple product variants are affected increases the attack surface significantly, as different deployment scenarios and configurations may be targeted. Security professionals must consider that attackers could leverage this vulnerability to establish persistent backdoors, escalate privileges, or deploy additional malware components through the compromised antivirus infrastructure. The vulnerability's remote exploitability means that attackers do not need physical access to systems or insider knowledge about network configurations to launch successful attacks. This characteristic aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the successful exploitation could enable attackers to execute arbitrary commands on compromised systems. Additionally, the vulnerability could be chained with other exploits to bypass security controls, making it particularly dangerous in enterprise environments where antivirus software serves as a primary defense mechanism.
Mitigation strategies for CVE-2005-2720 should prioritize immediate patching of affected HAURI products, as this represents the most effective defense against the vulnerability. Organizations must ensure that all instances of ViRobot Expert 4.0, Advanced Server, Linux Server 2.0, and LiveCall are updated to versions that address the buffer overflow in the vrAZace.dll library. System administrators should disable compressed file scanning functionality in affected products until patches are applied, as this reduces the attack surface by preventing the vulnerable library from being invoked during normal operations. Network segmentation and monitoring should be implemented to detect anomalous behavior that might indicate exploitation attempts, including unusual file processing patterns or unexpected system access. Security teams should also consider implementing network-based intrusion detection systems that can identify and block malicious ACE archive files containing oversized filenames. The vulnerability highlights the importance of proper input validation and memory management practices in security software, as the same principles that protect against this specific flaw should be applied throughout the entire codebase to prevent similar issues. Organizations should conduct thorough vulnerability assessments to identify other potential buffer overflow conditions in their security infrastructure and implement robust code review processes that include static analysis tools to detect memory corruption vulnerabilities before they can be exploited in production environments.