CVE-2013-5301 in Webfilter
Summary
by MITRE
Directory traversal vulnerability in help.php in Trustport Webfilter 5.5.0.2232 allows remote attackers to read arbitrary files via a .. (dot dot) in the hf parameter.
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Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-5301 represents a critical directory traversal flaw within the Trustport Webfilter 5.5.0.2232 application, specifically affecting the help.php component. This security weakness enables remote attackers to access arbitrary files on the affected system by manipulating the hf parameter through directory traversal sequences. The vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly restrict user-supplied data from navigating outside the intended directory structure. The flaw allows malicious actors to exploit the application's file handling routines by injecting .. (dot dot) sequences into the hf parameter, thereby bypassing normal access controls and potentially gaining unauthorized access to sensitive system files, configuration data, or other protected resources.
The technical implementation of this vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. This weakness occurs when applications fail to adequately validate or sanitize user-provided input before using it in file system operations. The Trustport Webfilter's help.php script processes the hf parameter without proper sanitization, allowing attackers to manipulate the file path resolution mechanism. When the application receives a request containing directory traversal sequences in the hf parameter, it fails to properly validate the input against a whitelist of acceptable values or to normalize the path to prevent upward directory navigation. This creates an exploitable condition where an attacker can traverse the file system hierarchy and access files that should remain restricted.
The operational impact of this vulnerability extends beyond simple file access, potentially enabling attackers to extract sensitive information, gain unauthorized system access, or escalate privileges within the affected environment. Remote attackers can leverage this flaw to access configuration files that may contain database credentials, system passwords, or other sensitive data. The vulnerability's remote exploitability means that attackers do not require physical access or local system credentials to exploit the weakness, making it particularly dangerous in networked environments. Additionally, successful exploitation could lead to further compromise of the webfilter appliance, potentially allowing attackers to modify system files, install malicious software, or use the compromised system as a pivot point for attacking other networked devices. The impact is further amplified by the fact that web filters typically operate with elevated privileges and may have access to sensitive network traffic data.
Mitigation strategies for CVE-2013-5301 should focus on implementing robust input validation and sanitization mechanisms within the Trustport Webfilter application. Organizations should immediately apply vendor-provided security patches or updates that address this specific vulnerability. The remediation approach should include implementing proper parameter validation that rejects or sanitizes directory traversal sequences before they can be processed by the application. Security measures should incorporate input whitelisting, path normalization, and strict access control mechanisms to prevent unauthorized file system access. Additionally, implementing network segmentation and access controls can help limit the potential impact of successful exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other applications and systems within the organization's infrastructure, following the principles outlined in the ATT&CK framework for privilege escalation and credential access techniques. The vulnerability demonstrates the importance of secure coding practices and proper input validation in preventing common web application security flaws that can lead to significant system compromise.