EMERGENCY PATCH NOW: SAP NetWeaver Flaw is a ‘Perfect 10’ Unauthenticated RCE

Last updated: October 15, 2025 (IST)TL;DR: A critical CVSS 10.0 vulnerability in SAP NetWeaver enables unauthenticated remote code execution under certain exposed configurations. If your SAP systems are internet-reachable or partner-accessible and lack tight network controls, an attacker can gain OS-level execution, exfiltrate ERP data (finance, HR, SCM), and pivot across your network. Patch immediately, restrict access to SAP services, rotate credentials, and hunt for post-exploitation indicators.What’s the Risk • Likely Affected Landscapes • Business & Compliance Impact • Emergency Mitigation & Hardening • How to Patch (Step-by-Step) • Threat Hunting & Detection Rules • FAQs

What’s the Risk

A logic flaw in a NetWeaver component reachable pre-auth allows crafted requests to execute arbitrary code on the SAP application host. Because NetWeaver underpins SAP ERP / ECC / S/4HANA ABAP stack, PI/PO, BW, Solution Manager and more, exploitation can yield SYSTEM/adm-level access, enabling data theft (PII/PHI/PCI), tampering with financial postings, and deployment of ransomware or stealthy web shells.

Related: Priority Guides & Services

Who’s Likely Affected

ABAP-based NetWeaver systems with HTTP/S or ICM services exposed to the internet or partner networks.
Dual-stack systems where Web Dispatcher forwards unauthenticated traffic to vulnerable endpoints.
Landscapes with outdated Support Packages or missing Security Notes on the relevant component.
Weak network segmentation (SAP in flat VLANs) or shared service accounts without MFA.

Business, Legal & Compliance Impact

Financial loss & downtime: Ransomware on app hosts, halted order processing, blocked invoicing.
Data breach: Payroll/HR, vendor bank details, price lists, customer PII, cardholder data via integrations.
Regulatory exposure: GDPR/UK-GDPR, DPDP Act (India), PCI DSS, SOX, HIPAA depending on modules/data.
Third-party risk: Compromise of EDI, supplier portals, and API partners.

Emergency Mitigation & Hardening (Do This Now)

Restrict exposure: If any SAP endpoints are internet-facing, temporarily restrict by IP or place behind a ZTNA/reverse proxy. Block unneeded methods/paths.
Turn on MFA: Enforce MFA for all admin and developer accounts (SAP*, DDIC, & technical users via IdP where possible).
ICM/Web Dispatcher: Add allowlists for known paths; deny unknown handlers; rate-limit suspicious patterns.
Credential hygiene: Rotate SAP service and RFC credentials; invalidate SSO tickets & trusted RFC relationships if compromise is suspected.
Backups & integrity: Snapshot app hosts and export profiles/kernel dirs; verify file integrity (profiles, DIR_INSTANCE, DIR_EXECUTABLE).

How to Patch (Step-by-Step)

Identify systems: In SAP Solution Manager/Focused Run or CMDB, list all NetWeaver systems by SID, instance, and kernel level. Include Dev/QA/Prod and DR.
Fetch official fixes: Log in to SAP for Me / SAP ONE Support Launchpad → Security Notes. Locate the current Note(s) addressing this RCE for your component and SP level.
Prereqs: Review prerequisite Support Packages, kernel patch levels, and SNOTE requirements (e.g., ST-PI/ST-A/PI updates).
Stage first: Import corrections in Dev → QA (ChaRM/CTS+). Run regression tests for login, RFC, printing, background jobs, PI/PO adapters.
Prod rollout window: Communicate downtime. Export transports to Prod; apply kernel/ICM patches as directed in the Note(s). Validate ICM restart and health.
Post-patch validation: Confirm disp+work status green, SMICM services running, HTTP(s) endpoints returning expected headers, and no errors in dev_icm / dev_w*.
Document: Record Note numbers, SP levels, kernel build, and evidence for audit (SOX/ISO 27001).

Threat Hunting & Detection (Blue Team)

HTTP patterns: Look for unusual pre-auth requests to rare ICF nodes, long query strings, or serialized payloads. Correlate 4xx storms followed by 200/500 responses.
Host traces: New or modified files in usr/sap/<SID>/SYS/exe, work/ web shells, or suspicious DLL/SO drops adjacent to kernel binaries.
Process anomalies: Child processes spawned by disp+work or ICM that execute shell commands or archivers.
Auth bypass signals: Spikes in anonymous HTTP sessions; SM20/SM21 showing failed then successful logons from the same remote IP block.
Net flow: Outbound connections to atypical ASNs from app hosts; lateral movement to DB hosts (HANA/AnyDB) after web activity.

SIEM ideas:

Alert on HTTP 500/503 bursts on SAP web paths from the same source within 5 minutes.
Watch for file writes under …/work/ or …/exe/ by the SAP service account after HTTP requests.
Detect new listening ports on SAP hosts (possible reverse shell bind).

FAQs

Is this confirmed to be exploited in the wild?

Treat it as imminently exploitable due to its pre-auth nature and high value of SAP data. Apply patches and detections regardless of current exploitation reports.

Which exact versions are vulnerable?

Vulnerability impact depends on component and Support Package levels. Always map your SP and kernel level against the latest SAP Security Notes for your release, then apply all corrective instructions.

We can’t patch today—what’s the minimum stopgap?

Restrict external access via reverse proxy/ZTNA, add IP allowlists, disable or remove unneeded ICF nodes, and monitor aggressively. Then schedule emergency change windows within 24–72 hours.

Does a WAF protect us?

A WAF can block some exploit patterns but is not a substitute for vendor patches. Use WAF rules as a compensating control while you patch.

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