CVE-2007-4761 in Barbo91
Summary
by MITRE
Unrestricted file upload vulnerability in upload.php in Barbo91 1.1 allows remote attackers to upload and execute arbitrary code via unspecified vectors. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 09/08/2018
The vulnerability identified as CVE-2007-4761 represents a critical security flaw in the Barbo91 1.1 web application's file upload functionality. This issue resides within the upload.php component and constitutes a classic unrestricted file upload vulnerability that enables remote attackers to bypass security controls and execute malicious code on the target system. The vulnerability's classification aligns with CWE-434 which specifically addresses the improper restriction of uploads of executable files, making it a significant concern for web application security. The attack vector involves an adversary exploiting the lack of proper file validation mechanisms to upload potentially harmful files that can be executed within the web server environment.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the file upload process. When users attempt to upload files through the vulnerable application, the system fails to properly verify file types, extensions, or content, allowing attackers to submit files with executable extensions or embedded malicious code. This flaw typically occurs when the application relies solely on client-side validation or permits file uploads without implementing server-side checks for file content and type. The unspecified vectors mentioned in the description suggest that multiple attack paths may exist, potentially including manipulation of file headers, use of double extensions, or leveraging server misconfigurations to bypass detection mechanisms.
The operational impact of this vulnerability extends far beyond simple unauthorized file placement. Remote attackers can leverage this weakness to upload web shells, malicious scripts, or other executable payloads that provide persistent access to the compromised system. Once successfully exploited, attackers can establish backdoors, escalate privileges, access sensitive data, or use the compromised server as a launch point for further attacks within the network. This vulnerability directly maps to several tactics in the MITRE ATT&CK framework including T1190 for exploitation of vulnerabilities in web applications, T1059 for execution through command and scripting interpreters, and T1078 for valid accounts and legitimate credentials. The potential for lateral movement and persistent access makes this vulnerability particularly dangerous in enterprise environments where the compromised server may serve as a foothold for broader network infiltration.
Mitigation strategies for CVE-2007-4761 require comprehensive implementation of multiple security controls to address the root cause of the vulnerability. Organizations should implement strict file type validation on the server-side, rejecting uploads of executable files or scripts regardless of their extension. The application must validate file content using magic number detection and perform proper sanitization of uploaded files. Additionally, uploaded files should be stored in a separate directory with restricted permissions and should not be directly served by the web server. Implementing Content Security Policies and using security headers can further reduce the attack surface. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other components of the application stack, while proper logging and monitoring mechanisms should be deployed to detect suspicious upload activities. The vulnerability also highlights the importance of keeping web applications updated with the latest security patches and following secure coding practices that prevent such flaws from being introduced in the first place.