On 09.06.2020 a security relevant correction has been released by SAP SE. The manufacturer resolves an issue within ABAP.
SAP Note 2541823 addresses "Switchable authorization checks for RFC in SAP CRM (external billing)" to prevent missing authorization check with a medium risk for exploitation.
A workaround does exist, according to SAP Security Advisory team. It is advisable to implement the correction as project***, the team suggests.
Missing authority checks are still the most common security defect related to authorizations in custom code. Since SAP uses an explicit authorization model, an authority checks must be coded in order to be executed. If an explicit check is not coded, all users have access. This type of vulnerability not only exists in SAP standard it also exists in customer coding. Check your custom developments for vulnerabilities that pose a risk to your systems. SecurityBridge helps detect code vulnerabilities before they are implemented in production.
An authenticated attacker can execute business function via calling function modules from remote without being properly authorized with business authorizations.
Additional authorization checks are introduced via the Switchable Authorization Framework (SACF) for new authorization object V_VBAK_AAT, function modules CRM_DELETE_OBSOLETE_DMR_ITEM, CRM_READ_DMR_ITEMS_FOR_CRM_SER, CRM_READ_DMR_ITEMS_FOR_CRM_W_D for Scenario CRM_SRV_EXT_BILLING - CRM External Billing RFC FM for Correction Reports And the good news are: a workaround exists, too! This was suggested by the SAP security experts: "Maintain strict governance on object S_RFC (no "*" in function groups or names) in all user roles. Alternatively, implement UCON and switch off remote capability of unused function modules."
The advisory 2541823 describes a problem within an ABAP based systems of a specific version. Affected versions are described below. ABAP software is deployed in various software components and is widely used within the SAP product portfolio.
SAP NetWeaver Application Server (formally known as SAP Web Application Server) is a building block of SAP NetWeaver. It is the foundation for most software products developed by SAP SE. SAP NetWeaver systems exist with Java and/or ABAP stacks. The advisory could be relevant for single and dual-stack ABAP installations.
The advisory is valid for
- SAP_APPL 600 6
- SAP_APPL 602 6
- SAP_APPL 603 6
- SAP_APPL 604 6
- SAP_APPL 605 7
- SAP_APPL 606 6
- SAP_APPL 616 6
- SAP_APPL 617 7
- SAP_APPL 618 9
- SAPSCORE 116 2
- S4CORE 100 12
- S4CORE 101 18
- S4CORE 102 18
- S4CORE 103 20
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There is no disclosure of zero-day vulnerabilities. In such case, the platform only provides details on which version or signature updates are available within the SecurityBridge platform in order to monitor or measure the vulnerability
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