CVE-2004-1426 in Korweblog
Summary
by MITRE
Directory traversal vulnerability in index.php in KorWeblog 1.6.2-cvs and earlier allows remote attackers to read arbitrary files and execute arbitrary PHP files via .. (dot dot) sequences in the lng parameter.
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Analysis
by VulDB Data Team • 06/19/2019
The vulnerability described in CVE-2004-1426 represents a classic directory traversal flaw that affects the KorWeblog content management system version 1.6.2-cvs and earlier. This type of vulnerability falls under the CWE-22 category, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw exists in the index.php script where user input is not properly sanitized before being used to construct file paths, creating an opportunity for malicious actors to access files outside the intended directory structure.
The technical implementation of this vulnerability occurs through the manipulation of the lng parameter in the HTTP request. When attackers append .. (dot dot) sequences to the lng parameter value, they can navigate up the directory hierarchy and access files that should remain restricted. This occurs because the application directly incorporates user-supplied input into file path construction without proper validation or sanitization mechanisms. The vulnerability is particularly dangerous as it allows not only file reading but also arbitrary PHP file execution, which means attackers can potentially execute malicious code on the server. The exploitation process typically involves crafting URLs with encoded or decoded dot dot sequences that bypass normal path restrictions and access sensitive files such as configuration files, database credentials, or other system files.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass full system compromise potential. Attackers can leverage this weakness to access critical system files, potentially obtaining database connection details, administrator credentials, or other sensitive information that could lead to complete system takeover. The vulnerability affects the availability and integrity of the web application as attackers can execute arbitrary code on the server, modify system files, or even establish persistent backdoors. This type of attack can result in data breaches, service disruption, and unauthorized access to the underlying server infrastructure. The vulnerability also poses significant risk to the confidentiality of information stored within the web application, as attackers can read files that contain sensitive data such as user credentials, configuration settings, or business-critical information.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and sanitization mechanisms. The most effective approach involves filtering or rejecting any input containing directory traversal sequences such as .. or %2e%2e. The application should enforce strict path validation that ensures all file operations occur within predefined, safe directories. Implementing proper access controls and least privilege principles can also limit the damage that can be caused by such vulnerabilities. Additionally, the web application should be updated to a patched version of KorWeblog that addresses this specific vulnerability. Organizations should also consider implementing web application firewalls that can detect and block directory traversal attempts, as well as regular security assessments to identify similar vulnerabilities in other applications. The remediation process should include comprehensive testing to ensure that the fix does not break legitimate functionality while effectively preventing the exploitation of this path traversal vulnerability. This vulnerability aligns with ATT&CK technique T1059.007 for PHP and T1566.001 for malicious file execution, demonstrating how path traversal can lead to broader exploitation chains within web application environments.