CVE-2005-0923 in Norton System Works
Summary
by MITRE
The SmartScan feature in the Auto-Protect module for Symantec Norton AntiVirus 2004 and 2005, as also used in Internet Security 2004/2005 and System Works 2004/2005, allows attackers to cause a denial of service (CPU consumption and system crash) by renaming a file on a network share.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability described in CVE-2005-0923 represents a critical denial of service flaw within Symantec Norton AntiVirus products that affected multiple versions including 2004 and 2005 editions. This issue specifically resides within the SmartScan feature of the Auto-Protect module, which serves as a core component for real-time threat detection and prevention. The flaw manifests when attackers exploit a weakness in how the system handles file operations on network shares, particularly through the manipulation of file renaming processes. The vulnerability operates at the intersection of network file system handling and antivirus protection mechanisms, creating a scenario where legitimate security functionality becomes a vector for system disruption. This type of vulnerability falls under CWE-400, which classifies it as an Uncontrolled Resource Consumption issue, where the system's resources are exhausted through improper handling of input data.
The technical exploitation of this vulnerability occurs when an attacker performs a file rename operation on a file located within a network share that is being monitored by the affected Symantec products. The SmartScan feature, designed to automatically scan files as they are accessed or modified, fails to properly handle the rename operation, leading to a condition where the antivirus software enters an infinite loop or consumes excessive CPU resources. This behavior results in significant performance degradation and can ultimately cause system crashes or complete system unresponsiveness. The impact is particularly severe in networked environments where multiple users may be accessing shared resources simultaneously, as the vulnerability can affect the entire network share and potentially propagate to multiple systems. The flaw demonstrates a classic example of insufficient input validation and inadequate error handling in security software components, where the system does not properly account for edge cases in file system operations.
From an operational standpoint, this vulnerability presents a substantial risk to enterprise environments that rely on Symantec's security solutions for network protection. The denial of service impact directly affects business continuity and can result in significant productivity losses when critical systems become unresponsive. Organizations using affected versions of Norton AntiVirus may experience cascading failures as the system resources are consumed, potentially leading to complete service outages. The vulnerability also creates opportunities for attackers to use this flaw as a preliminary step in more sophisticated attacks, as the system instability can mask other malicious activities or provide a distraction while more serious exploits are deployed. Network administrators face the challenge of identifying and mitigating this threat without disrupting legitimate security operations, as the vulnerability exists within the core protection mechanisms of the software.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems, as Symantec would have released updates to address the specific flaw in the SmartScan functionality. Organizations should implement network monitoring to detect unusual file rename activities that could indicate exploitation attempts, and establish baseline performance metrics to quickly identify when systems are being impacted by resource exhaustion. The principle of least privilege should be enforced to limit the scope of potential impact, ensuring that network shares are properly secured and that unnecessary file access permissions are removed. Additionally, implementing intrusion detection systems that can identify abnormal behavior patterns related to file system operations can provide early warning of exploitation attempts. This vulnerability aligns with ATT&CK technique T1499, which covers Network Denial of Service, and demonstrates how legitimate security tools can be weaponized to create system instability. Organizations should also consider implementing redundant security measures and backup systems to maintain operational continuity during remediation efforts, as the vulnerability affects core system functionality rather than merely providing additional protection layers.