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 3053066
was released on
08.06.2021 and deals with
"[CVE-2021-27635] Missing XML Validation in SAP NetWeaver AS for JAVA" within Java.
We advice you to follow the instructions, to resolve
external entity tunneling (xxe)
high potential for exploitation
in component BC-ESI-WS-JAV-CFG.
According to SAP Security Advisory team a workaround does not exist. It is advisable to implement the correction as part of maintenance.
Risk specificationSAP Netweaver AS for Java does not sufficiently validate uploaded XML entities allowing an authenticated user with basic privileges to inject some arbitrary XML entities leading to internal file disclosure or fully compromise availability by causing the system to crash. The attack cannot be used to change any data so that there is no compromise as to integrity.
The XML parser is now configured securely to validate submitted XML documents so that external entities are not allowed.
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
- ESP_FRAMEWORK 7.20 2
- ESP_FRAMEWORK 7.30 2
- ESP_FRAMEWORK 7.31 2
- ESP_FRAMEWORK 7.40 2
- ESP_FRAMEWORK 7.50 2
- 9.6 [CVE-2020-26831] Missing XML Validation in SAP BusinessObjects Business Intelligence Platform (Crystal Report)
- 9.3 [CVE-2020-6238] Missing XML Validation vulnerability in SAP Commerce
- 7.7 [CVE-2020-6285] Information Disclosure in SAP NetWeaver (XMLToolkit for Java)
- 7.6 [CVE-2020-6366] Missing XML Validation in SAP NetWeaver (Compare Systems)
- 7.1 [CVE-2019-0396] Missing XML Validation vulnerability in SAP BusinessObjects Business Intelligence Platform (Web Intelligence HTML interface)