CVE-2026-27565 Overview
CVE-2026-27565 is an unauthenticated remote command injection vulnerability [CWE-78] that allows attackers to upload a malicious IODD file. The upload triggers the placement and execution of a shell script running with root privileges. The malicious script persists across system reboots, giving attackers durable control of the affected device.
The vulnerability was published to the National Vulnerability Database (NVD) on 2026-09-16 and coordinated through CERT@VDE advisories VDE-2026-014, VDE-2026-027, and VDE-2026-028.
Critical Impact
Unauthenticated network attackers can achieve persistent root code execution on affected devices without user interaction.
Affected Products
- Products covered under CERT@VDE advisory VDE-2026-014
- Products covered under CERT@VDE advisory VDE-2026-027
- Products covered under CERT@VDE advisory VDE-2026-028
Discovery Timeline
- 2026-09-16 - CVE-2026-27565 published to NVD
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-27565
Vulnerability Analysis
The flaw resides in the handling of IODD (IO-Link Device Description) file uploads. IODD files describe IO-Link device parameters and are typically consumed by industrial gateways, masters, or engineering tooling. The affected product accepts an IODD file from an unauthenticated network user and processes its contents in a way that permits arbitrary shell command construction.
An attacker crafts an IODD file that causes the server-side processing routine to write a shell script to disk and execute it as root. Because the resulting script is placed in a location that survives reboot, the attacker achieves persistence without additional exploitation steps. The vulnerability maps to CWE-78, OS Command Injection.
Root Cause
The root cause is improper neutralization of special elements passed from the uploaded IODD file into an operating system command. The upload handler does not authenticate the requester, does not validate file contents against the IODD schema in a security-relevant way, and does not sanitize fields that reach a shell interpreter. This combination lets attacker-controlled data enter a privileged command context.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker sends a specially crafted IODD file to the exposed upload endpoint of a vulnerable device. Server-side processing writes and invokes a shell script with root privileges. The script is stored persistently, so the attacker retains code execution after the device restarts.
No verified proof-of-concept code is publicly available. Refer to the CERT VDE Advisory VDE-2026-014, CERT VDE Advisory VDE-2026-027, and CERT VDE Advisory VDE-2026-028 for vendor-specific technical detail.
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Stop Exploit AttemptsDetection Methods for CVE-2026-27565
Indicators of Compromise
- Unexpected IODD file uploads to device management endpoints from unknown source addresses.
- New or modified shell scripts under system directories that persist across reboots.
- Root-owned processes spawned by device management services shortly after an HTTP or FTP upload.
- Outbound network connections initiated by the device to attacker-controlled infrastructure after an IODD import event.
Detection Strategies
- Inspect network traffic for unauthenticated file uploads to IODD import endpoints on industrial gateways and IO-Link masters.
- Baseline device firmware and filesystem state, then alert on unauthorized additions to init, rc, systemd, or cron locations.
- Correlate IODD upload events with subsequent shell process creation under root context.
Monitoring Recommendations
- Enable and forward device audit logs to a centralized log platform for correlation and retention.
- Monitor for anomalous child processes of the device web or configuration service, particularly /bin/sh or /bin/bash.
- Track configuration and firmware integrity using vendor-provided attestation or file hash baselines.
How to Mitigate CVE-2026-27565
Immediate Actions Required
- Restrict network access to affected device management interfaces to trusted engineering workstations only.
- Place vulnerable devices behind a segmented OT firewall and block unauthenticated ingress from IT and external networks.
- Audit devices for unexpected persistent scripts and rebuild affected units from a known-good firmware image if compromise is suspected.
Patch Information
Consult the CERT VDE Advisory VDE-2026-014, CERT VDE Advisory VDE-2026-027, and CERT VDE Advisory VDE-2026-028 for vendor-supplied patches, firmware updates, and product-specific fixed versions. Apply the vendor-recommended firmware release for each affected product line.
Workarounds
- Disable the IODD upload feature on the device where operationally feasible until patched firmware is deployed.
- Enforce network access control lists that permit IODD imports only from authorized engineering hosts.
- Require VPN or jump-host access for any administrative interaction with affected devices.
- Monitor and alert on any file upload activity to the affected endpoint during the mitigation window.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
