CVE-2023-42362 in Teller Web App
Summary
by MITRE • 09/15/2023
An arbitrary file upload vulnerability in Teller Web App v.4.4.0 allows a remote attacker to execute arbitrary commands and obtain sensitive information via uploading a crafted file.
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Analysis
by VulDB Data Team • 02/02/2026
The CVE-2023-42362 vulnerability represents a critical arbitrary file upload flaw in the Teller Web App version 4.4.0 that exposes organizations to significant remote exploitation risks. This vulnerability falls under the category of insecure file handling practices where the application fails to properly validate or sanitize file uploads, creating an avenue for attackers to bypass security controls and execute malicious code. The flaw specifically manifests when the web application processes user-uploaded files without adequate restrictions on file types, extensions, or content validation, allowing malicious actors to upload potentially harmful files that can be executed within the application's context. The vulnerability's severity is compounded by the fact that it enables remote code execution capabilities, meaning attackers can directly influence the application's behavior and potentially compromise the underlying system. The impact extends beyond simple file manipulation as it provides attackers with the ability to obtain sensitive information, making this a multi-faceted threat that can lead to complete system compromise.
The technical exploitation of this vulnerability involves an attacker crafting malicious files that can be uploaded through the application's file upload interface and subsequently executed by the web server or application. This typically occurs when the application accepts file uploads without proper validation of file type, size, or content, allowing attackers to upload files with dangerous extensions such as .php, .jsp, .asp, or other executable formats. The vulnerability demonstrates a classic lack of input validation and sanitization that aligns with CWE-434, which specifically addresses insecure file upload vulnerabilities where applications fail to properly validate uploaded files. Attackers can leverage this weakness to upload web shells, malicious scripts, or other payloads that provide persistent access to the compromised system. The execution of arbitrary commands through this vulnerability enables attackers to perform reconnaissance, escalate privileges, and potentially move laterally within the network infrastructure.
The operational impact of CVE-2023-42362 extends far beyond the immediate compromise of the vulnerable application, as it creates persistent threat vectors that can be leveraged for extended attacks. Organizations using Teller Web App version 4.4.0 face potential data breaches, system compromise, and unauthorized access to sensitive information that could include customer data, financial records, or proprietary business information. The vulnerability's remote nature means that attackers can exploit it without requiring physical access to the system, making detection and prevention more challenging. From a threat actor perspective, this vulnerability aligns with ATT&CK technique T1190 which involves exploiting vulnerabilities in web applications to gain initial access. The impact on business operations includes potential regulatory compliance violations, financial losses, reputational damage, and the requirement for extensive incident response activities. Organizations may also face legal consequences and penalties if sensitive data is compromised due to this vulnerability.
Mitigation strategies for CVE-2023-42362 require immediate implementation of multiple security controls to prevent exploitation. Organizations should implement strict file type validation and sanitization mechanisms that reject suspicious file extensions and content, ensuring that only known safe file types are accepted. The application should enforce proper file upload restrictions including size limits, content type validation, and mandatory file extension filtering. Security measures must include moving uploaded files outside the web root directory and implementing proper access controls to prevent direct execution of uploaded content. Network-level protections such as web application firewalls and intrusion detection systems should be deployed to monitor for suspicious upload activities and block malicious file uploads. Regular security updates and patches should be applied immediately to address the vulnerability, with comprehensive testing to ensure that the fixes do not introduce new issues. Additionally, organizations should implement proper monitoring and logging of file upload activities to detect potential exploitation attempts and establish incident response procedures specifically tailored to handle file upload vulnerabilities. The remediation process should include thorough code reviews to identify similar vulnerabilities in other parts of the application and implementation of secure coding practices that prevent future occurrences of such flaws.