CVE-2009-4977 in MyBackup
Summary
by MITRE
PHP remote file inclusion vulnerability in index.php in MyBackup 1.4.0 allows remote authenticated users to execute arbitrary PHP code via a URL in the main_content parameter.
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Analysis
by VulDB Data Team • 07/13/2025
The vulnerability identified as CVE-2009-4977 represents a critical remote file inclusion flaw in the MyBackup 1.4.0 web application that exposes organizations to arbitrary code execution risks. This vulnerability specifically affects the index.php file within the application's codebase, where user input is improperly validated and processed. The flaw exists in the handling of the main_content parameter, which accepts URL values that are directly incorporated into the application's execution flow without adequate sanitization or validation. This type of vulnerability falls under the category of CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and aligns with the ATT&CK technique T1190 for "Exploit Public-Facing Application" as it targets a web interface that can be accessed remotely.
The technical exploitation of this vulnerability requires an authenticated user to leverage the parameter injection capability within the main_content field. When a malicious URL is provided through this parameter, the application's code execution flow processes the URL as if it were a local file path, potentially leading to the inclusion and execution of remote PHP scripts. The authentication requirement does not significantly mitigate the risk as it merely lowers the barrier to exploitation rather than eliminating it entirely. Attackers can craft malicious URLs that point to remote servers hosting malicious PHP payloads, which are then executed within the context of the vulnerable web application's privileges. This creates a direct pathway for attackers to execute arbitrary code, potentially leading to complete system compromise or data exfiltration.
The operational impact of this vulnerability extends beyond simple code execution to encompass broader security implications for affected organizations. Once exploited, attackers can gain persistent access to the compromised system, potentially using the vulnerability as a foothold for further reconnaissance and lateral movement within the network. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet without requiring physical access to the target environment. This characteristic makes it particularly dangerous as it can be exploited by threat actors without direct network access to the organization's infrastructure. Organizations using MyBackup 1.4.0 are particularly vulnerable as the flaw exists in the application's core functionality and cannot be easily mitigated through network-level defenses alone. The vulnerability also demonstrates poor input validation practices that are commonly associated with insecure coding patterns and can indicate broader security weaknesses within the application's architecture.
Mitigation strategies for CVE-2009-4977 should focus on immediate patching of the affected MyBackup 1.4.0 application to address the root cause of the vulnerability. Organizations should implement proper input validation and sanitization mechanisms to ensure that all user-supplied data is properly validated before being processed. The implementation of a whitelist approach for file inclusion operations, where only predefined and trusted file paths are allowed, provides an effective defense against similar vulnerabilities. Network-level protections such as web application firewalls and intrusion prevention systems can offer additional layers of defense by monitoring for suspicious URL patterns and parameter values. Security teams should also consider implementing strict access controls and authentication mechanisms to limit the number of users who can submit data to the vulnerable application. The vulnerability serves as a reminder of the importance of secure coding practices and proper input validation, as outlined in industry standards such as OWASP Top Ten and NIST guidelines for secure software development. Regular security assessments and code reviews should be conducted to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.