CVE-2026-94293: Asset Administration Shell Auth Bypass

CVE-2026-94293 Overview

CVE-2026-94293 is a missing authentication vulnerability [CWE-306] affecting Asset Administration Shell (AAS) implementations. An unauthenticated remote attacker can modify submodel data through HTTP PATCH requests and read all data exposed by GET endpoints. The flaw exposes industrial digital twin data to tampering and disclosure over the network. CERT-VDE published advisory VDE-2026-108 covering the issue.

Critical Impact
Remote attackers can read and modify Asset Administration Shell submodel data without any authentication, compromising the confidentiality and integrity of industrial digital twin assets.

Affected Products

Asset Administration Shell (AAS) submodel API implementation referenced in CERT-VDE advisory VDE-2026-108
Deployments exposing AAS GET and PATCH endpoints without authentication
Industrial systems relying on the affected AAS component for digital twin data exchange

Discovery Timeline

2026-10-06 - CVE CVE-2026-94293 published to the National Vulnerability Database (NVD)
2026-10-06 - Last updated in NVD database

Technical Details for CVE-2026-94293

Vulnerability Analysis

The vulnerability resides in the HTTP interface of an Asset Administration Shell submodel implementation. The service exposes GET endpoints for reading submodel data and PATCH endpoints for modifying it, but does not enforce authentication on either operation. A remote attacker with network reachability to the service can enumerate submodels, extract their contents, and overwrite submodel elements with attacker-controlled values.

Asset Administration Shells function as standardized digital twins for industrial assets in Industry 4.0 architectures. Submodels carry operational data such as sensor readings, identification records, nameplate information, and process parameters. Unauthorized modification can propagate incorrect values into downstream manufacturing execution and control systems.

The CWE-306 classification confirms the root issue is missing authentication for a critical function rather than a flawed authentication implementation. Consult CERT-VDE Advisory VDE-2026-108 for the authoritative technical description.

Root Cause

The affected service does not require credentials or tokens on its REST endpoints. Authorization checks are absent from the PATCH handler used to update submodel elements and from the GET handlers used to retrieve submodel contents. Any client that can reach the HTTP port is implicitly treated as authorized.

Attack Vector

Exploitation requires only network access to the AAS endpoint. The attacker issues standard HTTP GET requests to enumerate and read submodel data, then issues PATCH requests to modify submodel elements. No user interaction, prior authentication, or elevated privileges are needed. Refer to the vendor advisory for endpoint-level technical details; no public proof-of-concept code is referenced in the available data.

Detection Methods for CVE-2026-94293

Indicators of Compromise

Unexpected HTTP PATCH requests to AAS submodel URIs from unknown source addresses
Submodel element values changing outside of scheduled engineering or operational workflows
Access log entries for AAS GET and PATCH endpoints lacking an authenticated session or API token
Network connections to the AAS service originating from outside documented client ranges

Detection Strategies

Enable verbose HTTP access logging on the AAS service and forward logs to a centralized analytics platform for review of PATCH activity
Baseline normal submodel update frequency and source identities, then alert on deviations
Deploy network-level inspection to flag unauthenticated REST traffic to AAS endpoints
Correlate AAS modification events with authorized change tickets to identify unapproved writes

Monitoring Recommendations

Monitor for enumeration patterns such as sequential GET requests across submodel identifiers
Track volume and source distribution of PATCH requests against AAS services
Alert when AAS endpoints are reachable from untrusted network segments or the public internet
Review audit trails of integrated manufacturing and control systems for anomalous data ingested from AAS sources

How to Mitigate CVE-2026-94293

Immediate Actions Required

Restrict network access to AAS endpoints to trusted management and operations networks using firewalls or network segmentation
Place the AAS service behind an authenticating reverse proxy or API gateway until a vendor patch is applied
Review CERT-VDE Advisory VDE-2026-108 for vendor-specific guidance and fixed versions
Audit submodel data for unauthorized modifications introduced before the mitigation window

Patch Information

Refer to CERT-VDE Advisory VDE-2026-108 for the authoritative list of fixed versions and vendor remediation instructions. No fixed version metadata is included in the NVD record at the time of publication.

Workarounds

Terminate PATCH requests at an upstream proxy that enforces mutual TLS or token-based authentication
Deploy allow-list access control lists limiting AAS clients to known engineering workstations and integration services
Disable the submodel API on exposed interfaces where read and write functionality is not operationally required
Monitor AAS traffic with network detection tooling and quarantine hosts issuing unauthorized PATCH requests

bash

# Example: restrict AAS service exposure with iptables to trusted subnet only
iptables -A INPUT -p tcp --dport 443 -s 10.20.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP