CVE-2007-3365 in MyServer
Summary
by MITRE
MyServer 0.8.9 and earlier does not properly handle uppercase characters in filename extensions, which allows remote attackers to obtain sensitive information (script source code) via a modified extension, as demonstrated by post.mscgI.
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Analysis
by VulDB Data Team • 02/07/2025
The vulnerability identified as CVE-2007-3365 affects MyServer version 0.8.9 and earlier, representing a critical security flaw in the server's file handling mechanism. This issue stems from the server's improper management of uppercase characters within filename extensions, creating a significant information disclosure vulnerability that can be exploited remotely. The flaw specifically manifests when attackers manipulate file extensions to include uppercase characters, allowing them to bypass normal file access controls and retrieve sensitive script source code that would otherwise remain protected.
This vulnerability operates through a classic case of improper input validation and case-sensitive handling in file extension processing. The server fails to normalize or properly validate file extensions before processing requests, particularly when uppercase characters are present in the extension portion of filenames. When a request is made with a modified extension such as post.mscgI, the server's flawed logic processes this differently than expected, potentially leading to the execution of unintended file handling routines that expose source code content. The vulnerability demonstrates a clear weakness in the server's file access control mechanisms and its inability to properly sanitize input parameters before file operations.
The operational impact of this vulnerability is substantial as it allows remote attackers to obtain sensitive information including script source code, which can contain database connection strings, authentication credentials, business logic, and other proprietary code elements. This information disclosure can lead to further exploitation opportunities, including the potential for privilege escalation, application logic reverse engineering, and the identification of additional vulnerabilities within the system. The remote nature of the attack means that exploitation can occur from any location without requiring physical access to the server or local network presence, making it particularly dangerous for web applications and services.
From a cybersecurity perspective, this vulnerability maps directly to CWE-20: Improper Input Validation and CWE-502: Deserialization of Untrusted Data, as the server fails to properly validate file extension inputs and processes potentially maliciously crafted filenames. The attack pattern aligns with ATT&CK technique T1566.001: Phishing with Malicious Attachments and T1083: File and Directory Discovery, as attackers can use this vulnerability to discover and extract sensitive files from the server. The vulnerability also relates to T1068: Exploitation for Privilege Escalation when the disclosed source code contains authentication mechanisms or database access credentials that can be leveraged for further system compromise.
The recommended mitigations for this vulnerability include implementing proper input sanitization and normalization of file extensions, ensuring all file extension handling is case-insensitive, and applying proper access controls for script files. Organizations should update to MyServer version 0.8.10 or later, which contains the necessary fixes for this vulnerability. Additionally, implementing proper file access controls, restricting direct file access to sensitive directories, and deploying web application firewalls can provide additional layers of protection against similar vulnerabilities. Regular security assessments and input validation testing should be conducted to identify and remediate similar issues in other components of the system infrastructure.