CVE-2021-41645 in Budget and Expense Tracker System
Summary
by MITRE • 10/29/2021
Remote Code Execution (RCE) vulnerability exists in Sourcecodester Budget and Expense Tracker System 1.0 that allows a remote malicious user to inject arbitrary code via the image upload field. .
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Analysis
by VulDB Data Team • 11/04/2021
The CVE-2021-41645 vulnerability represents a critical remote code execution flaw within the Sourcecodester Budget and Expense Tracker System version 1.0, exposing organizations to significant cybersecurity risks. This vulnerability stems from inadequate input validation mechanisms within the application's image upload functionality, creating a pathway for malicious actors to bypass security controls and execute arbitrary code on the affected system. The flaw specifically targets the file upload processing component, where insufficient sanitization of user-supplied data enables attackers to upload malicious files that can be executed as part of the application's normal operations.
The technical implementation of this vulnerability aligns with common web application security weaknesses classified under CWE-434, which addresses insecure file upload handling. Attackers can exploit this weakness by crafting malicious files with specific extensions or embedded payloads that are not properly validated during the upload process. The vulnerability exists because the application fails to implement proper file type checking, content validation, or secure file storage mechanisms. When a user uploads an image file, the system does not adequately verify that the uploaded content matches the claimed file type, allowing attackers to upload files containing malicious code that can be executed in the context of the web server.
The operational impact of this vulnerability extends beyond simple code execution, potentially enabling attackers to gain full control over the affected system. Once exploited, the vulnerability allows malicious actors to perform actions such as data exfiltration, system enumeration, privilege escalation, and persistent access to the compromised environment. This represents a significant threat to the confidentiality, integrity, and availability of the budget and expense tracking data, which typically contains sensitive financial information and personal details of users. The vulnerability can be exploited remotely without requiring authentication, making it particularly dangerous as it can be targeted by automated scanning tools and exploited at scale.
Organizations should implement immediate mitigations including input validation, file type restriction, and secure file handling practices to address this vulnerability. The recommended approach involves implementing strict file extension validation, content type checking, and ensuring that uploaded files are stored in non-executable directories. Additionally, organizations should consider implementing web application firewalls, regular security assessments, and comprehensive monitoring to detect and prevent exploitation attempts. The vulnerability also highlights the importance of following secure coding practices and adhering to industry standards such as those defined in the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should also consider implementing the ATT&CK framework's techniques related to file execution and privilege escalation to better understand and defend against potential exploitation paths. The remediation process should include thorough code review, dependency updates, and comprehensive security testing to ensure that similar vulnerabilities are not present in other components of the application.