CVE-2011-4810 in WHMCompleteSolution
Summary
by MITRE
Multiple directory traversal vulnerabilities in WHMCompleteSolution (WHMCS) 3.x and 4.x allow remote attackers to read arbitrary files via the templatefile parameter to (1) submitticket.php and (2) downloads.php, and (3) the report parameter to admin/reports.php.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability identified as CVE-2011-4810 represents a critical directory traversal flaw affecting WHMCompleteSolution versions 3.x and 4.x, with implications for web application security and data confidentiality. This vulnerability stems from insufficient input validation within the application's file handling mechanisms, specifically in three distinct endpoints that process user-supplied parameters. The affected files include submitticket.php, downloads.php, and admin/reports.php, each of which processes templatefile and report parameters without adequate sanitization or access control measures. The vulnerability manifests when remote attackers exploit the lack of proper parameter validation to manipulate file paths and access unauthorized system resources.
The technical implementation of this directory traversal vulnerability follows the classic pattern where user-controllable input directly influences file system operations. When the templatefile parameter is submitted to submitticket.php or downloads.php, or when the report parameter is used in admin/reports.php, the application fails to properly validate or sanitize these inputs before using them in file system operations. This allows attackers to append directory traversal sequences such as "../" to navigate outside the intended directory structure and access arbitrary files on the server. The vulnerability operates at the application layer and can be exploited through HTTP requests without requiring authentication, making it particularly dangerous for publicly accessible web applications.
The operational impact of CVE-2011-4810 extends beyond simple file disclosure, potentially exposing sensitive system information including configuration files, database credentials, and application source code. Attackers could leverage this vulnerability to gain insights into the application's architecture, identify potential additional attack vectors, and access administrative interfaces that might contain further sensitive data. The vulnerability affects the confidentiality aspect of the CIA triad, as unauthorized file access directly compromises sensitive information. Organizations running affected WHMCS versions face significant risk of data breaches, especially those handling customer information, payment details, or administrative credentials. The vulnerability also creates potential for privilege escalation if attackers can access administrative files or configuration data that might reveal authentication mechanisms.
Security professionals should recognize this vulnerability as aligning with CWE-22 Directory Traversal and CWE-312 Cleartext Storage of Sensitive Information, while also mapping to ATT&CK techniques including T1083 File and Directory Discovery and T1566 Phishing. The recommended mitigations include immediate patching of affected WHMCS installations to versions that properly validate and sanitize user inputs. Organizations should implement input validation measures such as whitelisting acceptable parameter values, implementing proper path normalization, and restricting file access to intended directories only. Additional protective measures include monitoring for suspicious file access patterns, implementing web application firewalls, and conducting regular security assessments to identify similar vulnerabilities in other application components. The vulnerability demonstrates the critical importance of proper input validation and access control mechanisms in preventing unauthorized file system access within web applications.