Advisory

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) with a 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 specification

Knowledgement 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.

Solution

The application now properly checks the content submitted by the user and prohibits deserialization attacks.

Affected System

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

KMC-CM 7.01-7.02
KMC-CM 7.30 ⁶
KMC-CM 7.31 ⁶
KMC-CM 7.40 ⁶
KMC-CM 7.50 ⁶

Releated advisories

Disclaimer

SecurityBridge takes the security of SAP products very seriously. We very much encourage the responsible disclosure of security vulnerabilities. If you have detected a vulnerability concerning one of the SAP software products – either in the latest or in a former product version follow the guidelines and processes in accordance with the SAP portal page “Report a Security Vulnerability to SAP”.

The advisories found within the SecurityBridge advisory are generated and continuously enriched by our Team at SecurityBridge and affiliated security consultants, partners, customers of the SecurityBridge Platform, SAP support, and advisory groups.

We do not disclose zero-day vulnerabilities unless a security patch has been made available to the public. 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.

In accordance with SAP guidelines, SecurityBridge only discloses issues where the fixing security note has been released. The vulnerability platform makes no references to available exploits or Proof of Concepts (PoC). Advisories and vulnerabilities will always mention the fixing security note or hints to the corresponding SAP documentation.

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Notifications

Affected system Java

CVSS 6.5

Component EP-KM-CM-UI

Patch Day2021-03

Released on2021/03/09

SAP Note 2983436

Workaround No

Advisory

Risk specification

Solution

Affected System

Disclaimer

_{Affected system}
Java

_CVSS
6.5

_Component
EP-KM-CM-UI

_{Patch Day}
2021-03

_{Released
on}
2021/03/09

_{SAP Note}
2983436

_Workaround
No