CVE-2017-7280 in Enterprise Backup
Summary
by MITRE
An issue was discovered in api/includes/systems.php in Unitrends Enterprise Backup before 9.0.0. User input is not properly filtered before being sent to a popen function. This allows for remote code execution by sending a specially crafted user variable.
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Analysis
by VulDB Data Team • 08/30/2020
The vulnerability identified as CVE-2017-7280 represents a critical remote code execution flaw within the Unitrends Enterprise Backup software version 9.0.0 and earlier. This issue resides in the api/includes/systems.php file where user input undergoes insufficient validation before being processed through the popen function. The improper filtering creates an avenue for attackers to inject malicious commands that execute with the privileges of the affected system. Such vulnerabilities typically arise from inadequate input sanitization practices and demonstrate a fundamental failure in the application's security design.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious user variable that bypasses the expected input validation mechanisms. The popen function in php is particularly dangerous when fed untrusted input as it allows for command execution within the operating system context. This vulnerability directly maps to CWE-77 which describes improper neutralization of special elements used in a command. The flaw enables attackers to execute arbitrary commands on the target system, potentially leading to full system compromise. The vulnerability is classified as a command injection attack vector that leverages the inherent trust placed in user-supplied data by the application.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it provides attackers with persistent access to the backup infrastructure. Given that Unitrends Enterprise Backup systems often handle sensitive organizational data, this vulnerability could enable attackers to access, modify, or exfiltrate critical backup information. The attack surface is particularly concerning for enterprise environments where backup systems serve as crucial recovery points and contain extensive historical data. The remote nature of the exploit means that attackers can leverage this vulnerability from any location without requiring physical access to the system, making it especially dangerous in networked environments.
Organizations should prioritize immediate remediation by upgrading to Unitrends Enterprise Backup version 9.0.0 or later, which contains the necessary patches to address this vulnerability. System administrators should implement network segmentation to limit access to backup systems and deploy intrusion detection systems to monitor for suspicious command execution patterns. Additional mitigations include implementing proper input validation at multiple layers, utilizing privilege separation techniques, and conducting regular security assessments of backup infrastructure. The vulnerability also aligns with ATT&CK technique T1059 which covers command and scripting interpreter, highlighting the importance of monitoring for unusual command execution patterns in enterprise environments. Organizations should also consider implementing web application firewalls to detect and block malicious input patterns targeting this specific vulnerability.