Advisory

A note with CVSS 5.3 for component BC-ABA-LA was released by SAP on 08.12.2020. The correction/advisory 2996479 was described with "[CVE-2020-26835] Cross-Site Scripting (XSS) vulnerability in SAP NetWeaver AS ABAP" and affects the system type ABAP.

A workaround does not exist, according to SAP Security Advisory team. It is advisable to implement the correction as monthly patch process .

The vulnerability addressed is Cross-Site Scripting (XSS) within ABAP.

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. Cross-site scripting (XSS) is the name of a class of security vulnerabilities that can occur in web-based applications. XSS combines all vulnerabilities that allow an attacker to inject HTML Markup and/or JavaScript into the front end of the affected web application.

XSS attacks can occur whenever the application dynamically creates its HTML/JavaScript/CSS content, which is passed to the user's web browser, and attacker-controlled values are used in this process. If these values are included in the generated code without proper validation and encoding, the attacker is able to include arbitrary coding snippets into the application's front end. The code is then rendered by the victim's web browser and interpreted in the victim's current authentication context.

Risk specification

SAP NetWeaver (ABAP Server) and ABAP Platform do not sufficiently encode user-controlled inputs, resulting in Cross-Site Scripting (XSS) vulnerability.

Solution

The URL parameters are now properly encoded to prevent a successful XSS attack.

Affected System

The advisory 2996479 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_BASIS 740 ⁸¹
SAP_BASIS 750-755 ¹¹

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 ABAP

CVSS 5.3

Component BC-ABA-LA

Patch Day2020-12

Released on2020/12/08

SAP Note 2996479

Workaround No

Advisory

Risk specification

Solution

Affected System

Disclaimer

_{Affected system}
ABAP

_CVSS
5.3

_Component
BC-ABA-LA

_{Patch Day}
2020-12

_{Released
on}
2020/12/08

_{SAP Note}
2996479

_Workaround
No