CVE-2005-0773 in Backup Exec
Summary
by MITRE
Stack-based buffer overflow in VERITAS Backup Exec Remote Agent 9.0 through 10.0 for Windows, and 9.0.4019 through 9.1.307 for Netware allows remote attackers to execute arbitrary code via a CONNECT_CLIENT_AUTH request with authentication method type 3 (Windows credentials) and a long password argument.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability described in CVE-2005-0773 represents a critical stack-based buffer overflow affecting VERITAS Backup Exec Remote Agent versions ranging from 9.0 through 10.0 for Windows and 9.0.4019 through 9.1.307 for Netware systems. This flaw exists within the authentication handling mechanism of the backup software's remote agent component, specifically when processing CONNECT_CLIENT_AUTH requests that utilize authentication method type 3, which corresponds to Windows credentials. The vulnerability stems from inadequate input validation and bounds checking in the processing of password arguments, creating a condition where maliciously crafted input can overwrite adjacent memory locations on the stack.
The technical implementation of this vulnerability involves the remote agent receiving a specially crafted CONNECT_CLIENT_AUTH request containing an excessively long password argument. When the system processes this malformed input without proper bounds checking, the buffer overflow occurs during the authentication validation process, potentially allowing attackers to overwrite return addresses and other critical stack data. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory safety issue that has been consistently identified as one of the most prevalent and dangerous classes of vulnerabilities in software systems. The attack vector requires remote network access to the affected service, making it particularly concerning for enterprise environments where backup systems are often exposed to external networks.
The operational impact of this vulnerability extends beyond simple code execution, as successful exploitation could enable attackers to gain complete control over the affected backup agent processes, potentially leading to unauthorized data access, system compromise, and lateral movement within the network infrastructure. Backup systems often contain sensitive information and may operate with elevated privileges, making them attractive targets for attackers seeking persistent access. The vulnerability affects systems running VERITAS Backup Exec across multiple versions, indicating a widespread exposure that could impact numerous enterprise environments simultaneously. This type of attack aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, where attackers might leverage compromised backup agents to establish persistent backdoors or exfiltrate data through legitimate backup processes.
Mitigation strategies for this vulnerability should include immediate patching of affected VERITAS Backup Exec installations to the latest available versions that contain fixes for the buffer overflow condition. Organizations should also implement network segmentation to limit access to backup services, restrict remote access to backup agents, and deploy intrusion detection systems to monitor for suspicious CONNECT_CLIENT_AUTH requests. Additionally, security monitoring should focus on identifying unusually long password arguments or malformed authentication requests that could indicate exploitation attempts. The remediation process should also involve reviewing and hardening authentication mechanisms, implementing proper input validation, and ensuring that all network services undergo regular security assessments to identify similar buffer overflow conditions. Organizations should also consider implementing network access controls that limit which systems can communicate with backup agents and establish monitoring procedures to detect anomalous behavior in backup operations that could indicate compromise.