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 2973735
was released on
11.11.2020 and deals with
"[CVE-2020-26808] Code Injection in SAP AS ABAP and S/4 HANA (DMIS)" within ABAP.
We advice you to follow the instructions, to resolve
hot news potential for exploitation
in component CA-LT-PCL.
According to SAP Security Advisory team a workaround does not exist. It is advisable to implement the correction as monthly patch process .
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.
Risk specificationSAP AS ABAP and SAP S/4 HANA allows an authenticated attacker to inject arbitrary code in the application and change the course of execution. Due to lack of input validation, an attacker, who was granted access (S_RFC) to execute the function module can inject malicious ABAP code, which will be saved persistently in a report in the ABAP repository .
An authorization check (object S_DMIS, level 'Package', and activity value '01' - create and generate) is introduced in the affected function module, and the generated coding is removed/deleted from the ABAP repository. The generated report still exists but without any coding, therefore removing the possibility to exploit the identified vulnerability. In systems where the affected function module is not used the complete coding of the function module is commented out.
The advisory 2973735 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
- DMIS 2011_1_620 2
- DMIS 2011_1_640 2
- DMIS 2011_1_700 2
- DMIS 2011_1_710 2
- DMIS 2011_1_730 2
- DMIS 2011_1_731 2
- DMIS 2018_1_752 2
- DMIS 2020 2
- S4CORE 100 15
- S4CORE 101 21
- S4CORE 102 21
- S4CORE 103 24
- S4CORE 104 17
- S4CORE 105 3
ABEX takes the security of SAP products very seriously. We very much encourage the responsible disclosure of security vulnerabilities. If you have detected a vulnerability in 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 ABEX security advisory are generated and continuously enriched by ABEX and affiliated security consultants, partners, customers of the SecurityBridge security suite, SAP support, and advisory groups.
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
In accordance with SAP guidelines, ABEX only discloses issues where the fixing security note has been released at least three months ago. 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.