SAP takes the security of its vast product portfolio very seriously and thus releases security fixes for
vulnerabilities reported by external researchers and their customers every second Tuesday of the month.
SAP Note 2983436
was released on
09.03.2021 and deals with
"[CVE-2021-21488] Insecure deserialisation in SAP NetWeaver Knowledge Management" within Java.
We advice you to follow the instructions, to resolve
denial of service (dos)
medium potential for exploitation
in component EP-KM-CM-UI.
According to SAP Security Advisory team a workaround does not exist. It is advisable to implement the correction as part of maintenance.
Denial of Service (DoS) attacks that take a system offline may lead to significant cost for the company, studies quantify the costs in average between 4 and 5 millions dollars. Business continuity requires SAP systems staying online. The CVSS scores or vulnerability descriptions are not enough to represent how a simple bug can lead to a significant loss for companies.
Risk specificationKnowledgement management allows a remote attacker with basic privileges to deserialize user-controlled data without verification, leading to insecure deserialization and a Denial of Service thereby.
The application now properly checks the content submitted by the user and prohibits deserialization attacks.
SAP Netweaver Application Server Java is part of the SAP NetWeaver Application Platform. It provides the complete infrastructure for deploying and running Java applications.
- The AS Java Home: SAP Netweaver Application Server Java wiki
- A dedicated SAP NetWeaver 7.40 Application Server for Java Security Guide exists.
The advisory is valid for
- 9.8 Multiple Vulnerabilities in SAP Data Services
- 6.5 [CVE-2020-26826] Unrestricted File Upload vulnerability in SAP NetWeaver Application Server for Java (Process Integration Monitoring)
- 4.3 [CVE-2021-27592] Improper Input Validation in SAP 3D Visual Enterprise Viewer
- 4.3 [Multiple CVEs] Improper Input Validation in SAP 3D Visual Enterprise Viewer
- 4.3 [CVE-2020-26817] Improper input validation in Visual Enterprise Viewer