CVE-2020-6273 in S4 HANA
Summary
by MITRE
SAP S/4 HANA (Fiori UI for General Ledger Accounting), versions 103, 104, does not perform necessary authorization checks for an authenticated user working with attachment service, allowing the attacker to delete attachments due to Missing Authorization Check.
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Analysis
by VulDB Data Team • 11/08/2020
SAP S/4 HANA Fiori UI for General Ledger Accounting contains a critical authorization flaw that permits authenticated users to bypass necessary security controls when interacting with the attachment service functionality. This vulnerability affects versions 103 and 104 of the software, representing a significant weakness in the system's access control mechanisms. The flaw stems from the absence of proper authorization validation during attachment deletion operations, creating a scenario where users can manipulate files without appropriate permissions. This issue directly violates fundamental security principles and represents a clear violation of the principle of least privilege that should govern all enterprise applications.
The technical implementation of this vulnerability occurs within the attachment service component of the Fiori user interface, where the system fails to validate whether an authenticated user possesses the necessary privileges to perform deletion operations on attachments. This missing authorization check creates a path for privilege escalation where users can manipulate file systems through the web interface without proper authorization. The flaw specifically impacts the General Ledger Accounting module and operates at the application layer where user interactions with file attachments are processed. According to CWE classification, this represents a CWE-285: Improper Authorization vulnerability, which is categorized under the broader family of access control weaknesses that allow unauthorized operations within legitimate user sessions.
The operational impact of this vulnerability extends beyond simple file deletion capabilities and creates significant risks for financial data integrity and regulatory compliance. An attacker with valid credentials can exploit this weakness to remove critical financial documentation, potentially disrupting audit trails and financial reporting processes. This vulnerability particularly affects organizations that rely heavily on document management within their general ledger accounting workflows, as the deletion of attachments can result in loss of audit evidence and compliance violations. The attack surface is broadened by the fact that the vulnerability affects the Fiori UI, which is designed for broad user access, making it more likely to be exploited by both internal and external threat actors who can obtain legitimate user credentials.
Organizations should implement immediate mitigations including enhanced monitoring of attachment service operations, review of user access privileges, and implementation of additional controls beyond the default authorization mechanisms. The recommended approach involves strengthening the authorization checks within the attachment service to ensure that all operations are validated against user permissions before execution. Security teams should also consider implementing network segmentation to limit access to the affected modules and establish comprehensive audit logging for all attachment-related activities. This vulnerability aligns with ATT&CK technique T1078.004: Valid Accounts, which emphasizes how legitimate user credentials can be leveraged to perform unauthorized operations when proper access controls are absent. The mitigation strategy should also include regular security assessments of the Fiori UI components to identify similar authorization gaps that could be exploited in other modules of the SAP S/4 HANA platform.