Medium Severity
Affected system
Kernal
CVSS
4.7
Component
BC-FES-ITS
Patch Day
2021-02
Released on
2021/02/09
SAP Note
2973428
Workaround
No
  • Share with:

Advisory

A note with CVSS 4.7 for component BC-FES-ITS was released by SAP on 09.02.2021. The correction/advisory 2973428 was described with "Reverse Tabnabbing vulnerability within SAP NetWeaver Application Server ABAP (Applications based on SAP GUI for HTML)" and affects the system type Kernal.

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 reverse tabnabbing within Kernal.

Reverse tabnabbing is an attack where a page linked from the target page is able to rewrite that page, for example to replace it with a phishing site. The following figure shows a brief illustration:

Reverse Tabnabbing Overview
Source: OWASP.org

While the user was originally on the correct page there is a high risk they will not notice that it has been changed to a phishing site.

Risk specification

SAP GUI for HTML allows an unauthenticated remote attacker to redirect users to a malicious site due to insufficient reverse tabnabbing URL validation.

Solution

The solution impacts the method 'cl_gui_html_viewer'. Therefore, to resolve the issue the most current SAPEXE SAR for your kernel needs to be installed.

 

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.

SecurityBridge

SecurityBridgefor SAP©
empowers security teams with forward-looking, high fidelity, adversary-focused intelligence and actionable events from SAP Netweaver based systems.

Follow us