CVE-2018-1162 in NetVault Backup
Summary
by MITRE
This vulnerability allows remote attackers to create a denial-of-service condition on vulnerable installations of Quest NetVault Backup 11.2.0.13. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be easily bypassed. The specific flaw exists within the handling of Export requests. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to arbitrarily overwrite files resulting in a denial-of-service condition. Was ZDI-CAN-4222.
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Analysis
by VulDB Data Team • 01/03/2020
The vulnerability identified as CVE-2018-1162 represents a critical security flaw in Quest NetVault Backup version 11.2.0.13 that enables remote attackers to execute denial-of-service attacks through improper input validation. This vulnerability operates within the Export request handling functionality of the backup software, where insufficient validation of user-supplied paths leads to dangerous file operation behaviors. The flaw exists in the software's path validation mechanism, which fails to properly sanitize or verify input parameters before executing file system operations. According to CWE-22, this vulnerability stems from improper limitation of a pathname to a restricted directory, a common weakness that allows attackers to manipulate file system access through directory traversal attacks. The vulnerability's severity is amplified by the fact that while authentication is required for exploitation, the existing authentication mechanism can be easily bypassed, making the attack surface significantly broader than initially apparent.
The technical implementation of this vulnerability occurs when the system processes Export requests without adequate validation of file paths provided by users. When an attacker submits a malicious path string, the system fails to validate whether the path is within acceptable boundaries or contains dangerous sequences such as directory traversal characters. This allows the attacker to craft requests that can manipulate the file system to overwrite existing files or create arbitrary file operations that can cause system instability. The lack of proper input validation creates a condition where user-controllable data directly influences file system operations, which aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1489 for service stop. The vulnerability can be exploited to overwrite critical system files, corrupt backup data, or cause the application to crash, resulting in a denial-of-service condition that can render the backup system unusable for legitimate users.
The operational impact of CVE-2018-1162 extends beyond simple service disruption to encompass potential data integrity compromise and system availability degradation. Organizations relying on Quest NetVault Backup for critical data protection may face significant operational challenges when this vulnerability is exploited, particularly in environments where backup systems must remain available for disaster recovery operations. The vulnerability's potential for arbitrary file overwrites means that attackers could target configuration files, log files, or even critical system binaries, leading to cascading failures throughout the backup infrastructure. This type of vulnerability particularly affects enterprise environments where backup systems are centralized and critical for business continuity, making the impact of a successful attack potentially severe. The vulnerability's classification as a directory traversal issue means that it can be leveraged to access files outside of designated directories, potentially exposing sensitive backup data or system configuration information. The attack vector through Export requests suggests that this vulnerability could be exploited during normal backup operations, making detection more challenging as the malicious activity might appear to be legitimate system behavior.
Mitigation strategies for CVE-2018-1162 should focus on implementing proper input validation and access controls within the NetVault Backup system. Organizations should immediately apply the vendor-provided patches or updates that address the path validation flaw in the Export request handling functionality. Network segmentation and access control measures should be implemented to restrict access to the backup system to authorized personnel only, reducing the attack surface available to potential attackers. The implementation of proper authentication mechanisms and monitoring of Export request activities can help detect unauthorized access attempts. According to security best practices, organizations should also implement file integrity monitoring solutions that can detect unauthorized file modifications that might result from exploitation of this vulnerability. Regular security assessments and penetration testing of backup systems should be conducted to identify similar path traversal vulnerabilities that may exist in other components of the backup infrastructure. The vulnerability highlights the importance of implementing defense-in-depth strategies that include proper input validation, access controls, and continuous monitoring to protect critical backup systems from exploitation attempts.