CVE-2026-27564: API Endpoint Command Injection RCE Flaw

CVE-2026-27564 Overview

CVE-2026-27564 is an authenticated command injection vulnerability [CWE-78] affecting a device management API. A high-privileged remote attacker can send a crafted PUT request to the /api/datastorage/data endpoint using valid administrator credentials. The request triggers execution of operating system commands with root privileges on the underlying device.

The flaw enables full device compromise post-authentication, including persistence, lateral movement, and manipulation of stored data. CERT@VDE published three coordinated advisories (VDE-2026-014, VDE-2026-027, VDE-2026-028) referencing this issue.

Critical Impact
Authenticated administrators can escalate to root-level command execution on the device, resulting in full loss of confidentiality, integrity, and availability.

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-2026-27564 published to the National Vulnerability Database
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-27564

Vulnerability Analysis

The vulnerability resides in the /api/datastorage/data REST endpoint exposed by the affected device firmware. The endpoint processes PUT requests containing data storage parameters. Input supplied in the request body is passed to a shell interpreter without adequate sanitization or argument separation.

An attacker authenticated with administrative credentials can embed shell metacharacters within the request payload. The injected commands execute in the context of the root user, bypassing any application-layer privilege boundaries. Successful exploitation yields arbitrary code execution on the device operating system.

Because the attack requires valid admin credentials, exploitation depends on credential theft, insider access, weak or default administrator passwords, or chaining with an authentication bypass in the same product line. The EPSS score is approximately 2%, placing this CVE in the upper portion of scored vulnerabilities.

Root Cause

The root cause is improper neutralization of special elements used in an operating system command [CWE-78]. The endpoint constructs a shell command string using attacker-controlled input rather than invoking system utilities through parameterized APIs such as execve with argument arrays.

Attack Vector

Exploitation occurs over the network against the device's management interface. The attacker authenticates to the web API, then issues a PUT request to /api/datastorage/data containing a payload with shell metacharacters. The injected commands run as root, giving the attacker full control of the device, its stored data, and any downstream systems it communicates with.

No specific proof-of-concept code has been published. Refer to the CERT@VDE advisories linked below for vendor-supplied technical detail.

Detection Methods for CVE-2026-27564

Indicators of Compromise

Unexpected PUT requests to /api/datastorage/data originating from administrative sessions, especially with payloads containing shell metacharacters such as ;, |, &, `, or $().
New or unexpected root-owned processes on the device following administrative API activity.
Outbound network connections from the device to unfamiliar IP addresses, indicating possible reverse shells or C2 traffic.
Modifications to system binaries, cron entries, or startup scripts that do not correlate with authorized change windows.

Detection Strategies

Inspect web server and API access logs for PUT requests targeting the /api/datastorage/data route, correlating source IP, session identifier, and payload length.
Alert on administrator API sessions originating from IP ranges outside approved management networks.
Deploy network intrusion detection signatures that flag shell metacharacter patterns in JSON or form-encoded request bodies destined for device management APIs.

Monitoring Recommendations

Centralize device syslog, authentication events, and API access logs into a SIEM for correlation with authentication anomalies.
Baseline normal administrator activity per device and alert on deviations in request volume, endpoint mix, or off-hours access.
Monitor for privileged process creation events on managed devices and correlate with preceding HTTP transactions on the management interface.

How to Mitigate CVE-2026-27564

Immediate Actions Required

Apply the firmware updates referenced in CERT@VDE advisories VDE-2026-014, VDE-2026-027, and VDE-2026-028.
Rotate all administrator credentials on affected devices, and enforce strong, unique passwords.
Restrict the device management interface to a dedicated, isolated administration VLAN.
Audit administrator account activity for any suspicious use of the /api/datastorage/data endpoint prior to patching.

Patch Information

Refer to the CERT@VDE advisories listed above for vendor-specific patched firmware versions and update instructions. The advisories are the authoritative source for affected product identifiers, fixed release numbers, and vendor guidance.

Workarounds

Block network access to the /api/datastorage/data endpoint using an upstream reverse proxy or firewall rule when patching cannot be performed immediately.
Limit administrative API access to a small set of allow-listed source IP addresses.
Disable or restrict any administrator accounts that are not required for daily operations, and enable multi-factor authentication where the platform supports it.

bash

# Example firewall rule to restrict management API access to a jump host
iptables -A INPUT -p tcp --dport 443 -s 10.10.20.5 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP