CVE-2025-42987 is a medium-severity vulnerability affecting SAP SE's SAP S/4HANA product, specifically the Manage Processing Rules functionality for bank statements. The vulnerability is categorized under CWE-862, which indicates a missing authorization check. In this case, an attacker with basic privileges can manipulate request parameters to edit shared processing rules that belong to other users. These processing rules are critical for handling bank statement data within the SAP S/4HANA environment. Because the application fails to properly verify whether the requesting user is authorized to modify these shared rules, the attacker can alter rules that should be restricted. This compromises the integrity of the application by allowing unauthorized changes to business logic related to bank statement processing. The vulnerability affects multiple versions of SAP S/4HANA (S4CORE 104 through 108). The CVSS v3.1 base score is 4.3, reflecting a medium severity level. The vector indicates that the attack can be performed remotely over the network (AV:N), requires low attack complexity (AC:L), requires privileges (PR:L), does not require user interaction (UI:N), and impacts integrity only (I:L) without affecting confidentiality or availability. No known exploits are currently reported in the wild, and no patches have been linked yet. However, the vulnerability poses a risk because it allows privilege escalation within the application context by bypassing authorization controls, potentially leading to unauthorized modifications of financial processing rules.

For European organizations using SAP S/4HANA, especially those handling financial operations and bank statement processing, this vulnerability could lead to unauthorized modifications of critical business rules. Such unauthorized changes could result in incorrect processing of bank statements, financial discrepancies, or manipulation of transaction data integrity. This can undermine trust in financial reporting and compliance, potentially leading to regulatory issues under frameworks like GDPR and financial regulations such as MiFID II or PSD2. While the vulnerability does not directly expose confidential data or cause availability disruptions, the integrity compromise can have cascading effects on financial operations, audits, and internal controls. Given SAP's widespread adoption in Europe across industries such as manufacturing, finance, and public sector, the impact could be significant if exploited, especially in organizations with complex bank statement processing workflows. Attackers with basic privileges could leverage this flaw to escalate their influence within the SAP environment, potentially facilitating further attacks or fraud.

To mitigate this vulnerability, European organizations should: 1) Immediately review and restrict user privileges to the minimum necessary, ensuring that only trusted users have access to Manage Processing Rules functionality. 2) Implement strict monitoring and logging of changes to processing rules to detect unauthorized modifications promptly. 3) Apply SAP's official patches or security notes as soon as they become available for the affected S4CORE versions (104 to 108). 4) Conduct thorough security assessments and penetration testing focused on authorization controls within SAP S/4HANA modules. 5) Use SAP's security configuration tools to enforce role-based access controls and validate that authorization checks are correctly implemented. 6) Educate SAP administrators and users about the risks of parameter tampering and encourage vigilance against suspicious activities. 7) Consider implementing additional application-layer firewalls or SAP-specific security solutions that can detect and block anomalous requests targeting processing rules. These steps go beyond generic advice by focusing on privilege management, monitoring, and proactive security hygiene tailored to SAP environments.