CVE-2001-0959 in ARCserve Backup
Summary
by MITRE
Computer Associates ARCserve for NT 6.61 SP2a and ARCserve 2000 7.0 creates a hidden share named ARCSERVE$, which allows remote attackers to obtain sensitive information and overwrite critical files.
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Analysis
by VulDB Data Team • 10/01/2025
The vulnerability identified as CVE-2001-0959 represents a critical security flaw in Computer Associates ARCserve backup software versions 6.61 SP2a for NT and 7.0 for ARCserve 2000. This issue stems from the improper configuration of network shares during the software installation process, specifically creating a hidden share named ARCSERVE$ that persists on affected systems. The flaw falls under the category of insecure default configurations and weak privilege management, aligning with CWE-732 which addresses inadequate permissions for critical resources. The hidden share operates with elevated privileges and lacks proper access controls, creating a significant attack surface that violates fundamental security principles of least privilege and defense in depth.
The technical implementation of this vulnerability involves the software automatically establishing a network share without proper user awareness or explicit configuration. The ARCSERVE$ share typically provides access to backup-related directories and files, including configuration data, backup catalogs, and potentially sensitive backup content. Remote attackers can discover this hidden share through network enumeration tools or by leveraging default share discovery techniques, allowing them to access the share without authentication. This misconfiguration enables attackers to perform information disclosure operations by reading critical files and to execute file overwrite operations that could compromise backup integrity, potentially leading to data loss or system compromise. The vulnerability demonstrates poor security design practices and violates the principle of secure by default configurations.
The operational impact of CVE-2001-0959 extends beyond simple information disclosure to encompass potential system compromise and data integrity violations. Attackers exploiting this vulnerability could gain access to backup configurations that might reveal system architecture details, backup schedules, and potentially sensitive data contained within backup files. The ability to overwrite critical files through the hidden share presents a significant risk to backup operations, potentially allowing attackers to corrupt backup data or substitute malicious content. This vulnerability can be exploited by attackers at the network level using standard reconnaissance techniques, making it particularly dangerous in enterprise environments where backup systems often contain sensitive organizational data and system configurations. The impact aligns with ATT&CK technique T1005 for data from local system and T1486 for data encryption for ransomware, as the compromised backup system could be used to facilitate data destruction or encryption attacks.
Organizations affected by this vulnerability should implement immediate mitigations including disabling the problematic hidden share through manual configuration changes, applying available vendor patches or updates, and implementing network segmentation to limit access to backup servers. Network administrators should conduct thorough inventory checks to identify all affected systems and ensure proper access controls are implemented for backup shares. The remediation process should include disabling unnecessary shares, implementing proper authentication mechanisms, and conducting security audits of backup server configurations. Additionally, system administrators should review and update their backup security policies to prevent similar issues in the future, ensuring that all network shares are properly configured with appropriate access controls and that backup systems are isolated from unauthorized network access. This vulnerability highlights the importance of secure configuration management and proper security testing of backup and recovery systems.