CVE-2021-33698 in Business One
Summary
by MITRE • 09/16/2021
SAP Business One, version - 10.0, allows an attacker with business authorization to upload any files (including script files) without the proper file format validation.
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Analysis
by VulDB Data Team • 09/19/2021
SAP Business One version 10.0 contains a critical security vulnerability that enables authenticated attackers with business authorization levels to bypass file validation mechanisms and upload arbitrary files including malicious scripts. This vulnerability stems from insufficient input validation within the file upload functionality, creating an environment where attackers can exploit the system's trust in legitimate business users. The flaw represents a classic path traversal and arbitrary file upload vulnerability that can be leveraged for remote code execution and persistent system compromise.
The technical implementation of this vulnerability resides in the file upload handler's lack of proper file type validation and content inspection. When business users attempt to upload files through the application interface, the system fails to perform adequate checks on file extensions, MIME types, or actual file contents. This absence of validation allows attackers to upload files with extensions such as .jsp, .php, .asp, or .aspx that can execute server-side code when accessed through the web application. The vulnerability directly maps to CWE-434 Unrestricted Upload of File with Dangerous Type, which is categorized under the OWASP Top Ten as a critical security risk. Attackers can leverage this weakness to upload web shells, malicious scripts, or other payloads that can establish persistent access to the system.
The operational impact of this vulnerability is severe and multifaceted. An attacker with business authorization can gain unauthorized access to the underlying server infrastructure, potentially leading to complete system compromise and data exfiltration. The vulnerability enables lateral movement within the network as attackers can use the uploaded scripts to pivot to other systems or escalate privileges. This weakness can also result in service disruption, data corruption, and unauthorized modification of business data. The attack surface expands significantly since business users typically have elevated privileges within the SAP environment, making this a particularly dangerous vulnerability for organizations that grant broad business authorization rights.
Organizations should implement immediate mitigations including restricting file upload functionality to only trusted users, implementing strict file type validation with allowlists of approved extensions, and deploying web application firewalls to monitor and block suspicious upload attempts. The system should enforce proper file content inspection using file signature validation and MIME type verification rather than relying solely on file extensions. Security controls should include regular monitoring of upload directories for suspicious files, implementing least privilege access for business users, and conducting regular security assessments of the SAP Business One environment. Additionally, organizations should consider implementing the principle of least privilege as outlined in the MITRE ATT&CK framework, specifically targeting techniques such as T1059 Command and Scripting Interpreter and T1078 Valid Accounts to prevent unauthorized access through legitimate business user accounts. Regular patching and updates should be enforced to address this vulnerability and similar weaknesses in the SAP Business One platform.