CVE-2025-42948: SAP NetWeaver ABAP Platform XSS Flaw

CVE-2025-42948 Overview

CVE-2025-42948 is a Cross-Site Scripting (XSS) vulnerability [CWE-79] affecting the SAP NetWeaver ABAP Platform. An unauthenticated attacker can craft a malicious link and publish it publicly. When an authenticated user clicks the link, the injected input is processed during page generation and executed in the victim's browser context.

The flaw enables attackers to access or modify information within the scope of the victim's browser session. SAP addressed the issue as part of its monthly Security Patch Day release.

Critical Impact
An authenticated user who clicks an attacker-supplied link may have session data, tokens, or displayed content read or altered by injected script executing in the SAP NetWeaver web context.

Affected Products

SAP NetWeaver ABAP Platform
SAP web-facing components rendering user-controllable input
Deployments exposing NetWeaver pages to authenticated users

Discovery Timeline

2025-08-12 - CVE-2025-42948 published to NVD
2025-08-12 - SAP released fix via SAP Note #3629871 on Security Patch Day
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-42948

Vulnerability Analysis

The vulnerability is a reflected Cross-Site Scripting (XSS) flaw [CWE-79] in the SAP NetWeaver ABAP Platform. User-supplied input is embedded into a generated page without adequate output encoding or sanitization. When the browser renders the response, the injected payload executes as script under the origin of the SAP application.

Exploitation requires user interaction. The attacker must convince an authenticated user to follow a crafted link, which limits mass exploitation but suits targeted phishing scenarios against SAP administrators and business users.

The attack changes security scope. Injected script runs with access to the authenticated user's session context and any data reachable within the browser. Confidentiality and integrity impacts are limited, and availability is not affected.

Root Cause

The root cause is missing or inadequate neutralization of input during web page generation. Parameters supplied through the malicious URL flow into HTML output without proper contextual encoding, allowing script tags or event handlers to be interpreted by the browser rather than rendered as text.

Attack Vector

The attack vector is network-based and requires user interaction. An unauthenticated attacker crafts a URL containing an XSS payload targeting a vulnerable NetWeaver endpoint. The attacker distributes the link through email, chat, forums, or embedded content. When an authenticated SAP user clicks the link, the browser submits the payload, the server reflects it into the response, and the script executes in the victim's session context.

The vulnerability is described in prose only because no verified proof-of-concept code is publicly available. Refer to SAP Note #3629871 for vendor technical details.

Detection Methods for CVE-2025-42948

Indicators of Compromise

Inbound HTTP requests to SAP NetWeaver URLs containing <script>, onerror=, onload=, or encoded variants such as %3Cscript%3E in query parameters.
Reflected response bodies that echo request parameter values into HTML without encoding.
User reports of unexpected pop-ups, redirects, or session anomalies after clicking SAP-hosted links.

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect NetWeaver request parameters for XSS signatures and block or log matches.
Enable verbose HTTP request logging on SAP Web Dispatcher and Internet Communication Manager (ICM) to capture full URLs and referrers.
Correlate SAP application logs with proxy logs to identify authenticated sessions that followed externally sourced links.

Monitoring Recommendations

Alert on anomalous outbound requests from user browsers to attacker-controlled domains immediately after visiting SAP URLs.
Track SAP audit logs for unexpected transactions or data access performed shortly after suspicious link activity.
Monitor threat intelligence feeds for links referencing SAP NetWeaver hosts distributed in phishing campaigns.

How to Mitigate CVE-2025-42948

Immediate Actions Required

Apply the SAP patch referenced in SAP Note #3629871 to all affected NetWeaver ABAP Platform instances.
Inventory internet-exposed NetWeaver endpoints and prioritize patching for systems reachable by external phishing lures.
Notify SAP users about phishing campaigns and reinforce guidance against clicking unsolicited SAP links.

Patch Information

SAP issued a fix through SAP Note #3629871, published on SAP Security Patch Day. Administrators should review the note for the exact component versions and support package levels required.

Workarounds

Deploy WAF or reverse proxy rules that reject requests containing common XSS payload patterns targeting NetWeaver paths.
Enforce a strict Content Security Policy (CSP) on NetWeaver responses to limit inline script execution.
Restrict access to affected NetWeaver interfaces via network segmentation or VPN until the patch is deployed.

bash

# Example WAF rule concept (ModSecurity syntax) to block reflected XSS attempts
SecRule ARGS "@rx (?i)(<script|onerror=|onload=|javascript:)" \
    "id:1042948,phase:2,deny,status:403,\
    msg:'Potential XSS targeting SAP NetWeaver (CVE-2025-42948)',\
    tag:'CVE-2025-42948'"