CVE-2023-52262 in little-backup-box
Summary
by MITRE • 12/30/2023
outdoorbits little-backup-box (aka Little Backup Box) before f39f91c allows remote attackers to execute arbitrary code because the PHP extract function is used for untrusted input.
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Analysis
by VulDB Data Team • 01/22/2024
The outdoorbits little-backup-box represents a network backup solution that suffered from a critical remote code execution vulnerability identified as CVE-2023-52262. This vulnerability affects versions prior to f39f91c and stems from improper input validation within the application's PHP implementation. The flaw specifically exploits the use of the PHP extract function with untrusted data, creating a pathway for remote attackers to execute arbitrary code on the affected system. The vulnerability demonstrates a fundamental security issue in how the application processes user-supplied parameters, particularly those related to backup configurations and network operations.
The technical root cause of this vulnerability lies in the PHP extract function's behavior of creating variables from array keys and values, which when combined with untrusted input, allows attackers to inject malicious variables into the application's execution context. This function operates by taking an array and creating variables in the current symbol table with keys as variable names and values as variable values. When this function processes untrusted input without proper sanitization or validation, it enables attackers to manipulate the application's variable namespace and potentially overwrite critical variables or introduce new ones that can be exploited for code execution. This vulnerability directly maps to CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and specifically relates to CWE-74, "Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')". The attack vector is particularly dangerous as it requires no authentication, making it accessible to remote attackers who can leverage this weakness to gain full control over the backup server.
The operational impact of CVE-2023-52262 extends beyond simple code execution, as it provides attackers with complete control over the backup system's operations. Attackers can execute arbitrary commands with the privileges of the web server process, potentially leading to data exfiltration, system compromise, or further network infiltration. The vulnerability affects the backup functionality of the little-backup-box, which typically handles sensitive data and backup configurations. This compromise could result in unauthorized access to backup repositories, modification of backup schedules, or complete system takeover. The nature of backup systems makes them particularly attractive targets, as they often contain valuable data and may operate with elevated privileges. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1566.001 for "Phishing: Spearphishing Attachment", as attackers could leverage this weakness to establish persistent access and expand their operational capabilities.
Mitigation strategies for CVE-2023-52262 should focus on immediate patching of the affected software to version f39f91c or later, which addresses the improper use of the PHP extract function. Organizations should also implement network segmentation to limit access to backup systems and ensure that only authorized personnel can interact with these services. Input validation and sanitization measures should be strengthened throughout the application to prevent similar issues in the future. The implementation of Web Application Firewall rules to detect and block suspicious parameter patterns can provide additional protection layers. Security monitoring should include detection of unusual backup activities, unauthorized access attempts, and command execution patterns that may indicate exploitation of this vulnerability. Regular security assessments and code reviews should be conducted to identify and remediate similar injection vulnerabilities, particularly those involving dynamic variable creation functions. Organizations should also consider implementing principle of least privilege for web server processes and regularly audit backup configurations to ensure that access controls remain properly enforced.