Advisory

On 09.03.2021 a security relevant correction has been released by SAP SE. The manufacturer resolves an issue within Java.

SAP Note 2978151 addresses "Reverse tabnabbing issue in Unified Rendering based frameworks in NetWeaver Application Server Java" to prevent reverse tabnabbing with a medium risk for exploitation.

A workaround does not exist, according to SAP Security Advisory team. It is advisable to implement the correction as part of maintenance, the team suggests.

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

This note has been re-released with updated section "software components". Applications based on SAP Unified Rendering allows an unauthenticated remote attacker to redirect users to a malicious site due to insufficient reverse tabnabbing URL validation.

Solution

This note is a technical prerequisite for other UI Frameworks, the final fix itself will be delivered with the UI-Frameworks. Note you must ensure to update the corresponding SCA provided by: WebDynpro Java - Implement note 2976947 first and ensure to install the corresponding AJAX-RUNTIME.SCA provided by this note HTMLB - Implement note 2977001 first and ensure to install framework.sca and framework-ext.sca provided by this note

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

AJAX-RUNTIME 7.20
AJAX-RUNTIME 7.30
AJAX-RUNTIME 7.31
AJAX-RUNTIME 7.40
AJAX-RUNTIME 7.50
FRAMEWORK 7.10-7.11 ⁶
FRAMEWORK 7.20 ⁵
FRAMEWORK 7.30 ⁵
FRAMEWORK 7.31 ⁶
FRAMEWORK 7.40 ⁶
FRAMEWORK 7.50 ⁶
FRAMEWORK-EXT 7.30 ³
FRAMEWORK-EXT 7.31 ³
FRAMEWORK-EXT 7.40 ³
FRAMEWORK-EXT 7.50 ³
SAP_JTECHF 7.00 ²
SAP_JTECHS 7.00 ²

Releated advisories

Disclaimer

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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 4.7

Component BC-WD-UR

Patch Day2021-03

Released on2021/03/09

SAP Note 2978151

Workaround No

Advisory

Risk specification

Solution

Affected System

Disclaimer

_{Affected system}
Java

_CVSS
4.7

_Component
BC-WD-UR

_{Patch Day}
2021-03

_{Released
on}
2021/03/09

_{SAP Note}
2978151

_Workaround
No