CVE-2021-43674 in ThinkUp
Summary
by MITRE • 12/03/2021
** UNSUPPORTED WHEN ASSIGNED ** ThinkUp 2.0-beta.10 is affected by a path manipulation vulnerability in Smarty.class.php.
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Analysis
by VulDB Data Team • 08/04/2024
The vulnerability identified as CVE-2021-43674 affects ThinkUp version 2.0-beta.10 and stems from a path manipulation issue within the Smarty.class.php file. This represents a critical security flaw that could potentially allow attackers to manipulate file paths and gain unauthorized access to system resources. The vulnerability resides in the template processing component of the application, specifically within the Smarty templating engine implementation that ThinkUp utilizes for rendering user interfaces and dynamic content. Path manipulation vulnerabilities typically occur when applications fail to properly validate or sanitize file paths before processing them, creating opportunities for attackers to traverse directories and access unintended files or resources.
The technical flaw manifests when the Smarty templating engine processes user-supplied input or configuration parameters that influence file path resolution. Attackers can exploit this weakness by crafting malicious input that manipulates the path resolution logic to access files outside of the intended directory structure. This could enable unauthorized file access, directory traversal, and potentially lead to arbitrary code execution or data exposure. The vulnerability operates at the application level where input validation is insufficient, allowing path traversal sequences such as ../ or ..\ to be processed without proper sanitization. According to CWE classification, this vulnerability maps to CWE-22 Path Traversal which is categorized under the broader weakness of improper input validation and inadequate path handling mechanisms.
The operational impact of this vulnerability extends beyond simple file access, as it could enable attackers to escalate privileges, read sensitive configuration files, access database credentials, or potentially compromise the entire application environment. In a web application context, this vulnerability could allow an attacker to access system files that contain sensitive information such as database connection strings, API keys, or other administrative credentials. The risk is particularly significant for applications like ThinkUp that process user-generated content and may have complex file access patterns. The vulnerability could also facilitate further attacks by providing attackers with information about the underlying system architecture and file structure, which could be leveraged for more sophisticated exploitation techniques. This aligns with ATT&CK technique T1083 File and Directory Discovery which involves adversaries exploring the file system to understand the target environment.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms within the Smarty template processing logic. Organizations should ensure that all file path inputs are properly validated and normalized before processing, eliminating any potential path traversal sequences. The recommended approach includes implementing strict path validation that ensures all file operations occur within predetermined safe directories and implementing proper access controls to limit file system access. Additionally, updating to a supported and patched version of ThinkUp would provide the most effective remediation, as the affected version is marked as unsupported. Security measures should also include monitoring for unusual file access patterns and implementing web application firewalls that can detect and block malicious path traversal attempts. Regular security assessments and code reviews focusing on input validation practices would help identify and remediate similar vulnerabilities in other components of the application stack.