CVE-2011-1569 in Douran
Summary
by MITRE
download.aspx in Douran Portal 3.9.7.8 allows remote attackers to obtain source code of arbitrary files under the web root via (1) a trailing ".", (2) a trailing space, or (3) mixed case in the FileNameAttach parameter.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2011-1569 affects Douran Portal version 3.9.7.8 and represents a critical directory traversal flaw in the download.aspx component. This issue enables remote attackers to access arbitrary files within the web root directory by exploiting specific input manipulation techniques that bypass normal file access controls. The vulnerability stems from inadequate input validation and sanitization mechanisms within the FileNameAttach parameter processing logic, creating a pathway for unauthorized file retrieval that could expose sensitive source code and configuration files.
The technical exploitation of this vulnerability relies on three distinct attack vectors that leverage operating system file handling behaviors. The first vector involves appending a trailing period character to the filename parameter, which can cause the web application to interpret the request differently and potentially resolve to the parent directory or access files with unexpected path resolution. The second vector utilizes trailing whitespace characters that may be stripped or processed inconsistently by the application's file access routines, while the third approach employs mixed case character variations to exploit case-insensitive file systems or improper case normalization in the application's file resolution logic. These techniques collectively demonstrate a fundamental flaw in the application's security controls that fails to properly validate and sanitize user-supplied input before file system operations.
The operational impact of this vulnerability extends beyond simple information disclosure, as attackers can potentially access sensitive source code files that may contain database credentials, application logic, business rules, and other confidential information. The exposure of source code creates additional risks including the potential for further exploitation through identified code vulnerabilities, business logic flaws, or hardcoded secrets. This type of vulnerability aligns with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory and CWE-77 - Improper Neutralization of Special Elements used in a Command, as it allows attackers to manipulate file access paths and potentially execute unauthorized operations. The vulnerability also maps to ATT&CK technique T1213.002 - Data from Information Repositories, as it enables unauthorized access to repository contents through web application interfaces.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization controls within the application's file access routines. The most effective approach involves implementing strict parameter validation that rejects any input containing special characters, path traversal sequences, or unusual filename patterns before any file system operations are performed. Additionally, the application should enforce proper file access controls that restrict file operations to predefined directories and implement proper case normalization and whitespace handling to prevent the exploitation techniques described. Organizations should also consider implementing web application firewalls and input filtering mechanisms to detect and block suspicious requests targeting the vulnerable download.aspx component. Regular security testing and code reviews should be conducted to identify similar vulnerabilities in other application components, particularly those handling file operations or user-supplied parameters that interact with the file system.