CVE-2026-27547: Command Injection RCE Vulnerability

CVE-2026-27547 Overview

CVE-2026-27547 is a command injection vulnerability [CWE-78] affecting the /index.php/ajax/get_iodd_menu_info endpoint of an affected device's web management interface. A low-privileged remote attacker holding valid user or operator credentials can inject operating system commands that execute with root privileges. The flaw provides a direct path from authenticated low-privilege access to full device compromise. Coordination and disclosure were handled through CERT@VDE under advisories VDE-2026-014, VDE-2026-027, and VDE-2026-028.

Critical Impact
Authenticated attackers with user- or operator-level credentials can execute arbitrary OS commands as root, resulting in full device takeover, integrity loss, and denial of service.

Affected Products

Devices exposing the /index.php/ajax/get_iodd_menu_info web endpoint as described in CERT@VDE advisories VDE-2026-014, VDE-2026-027, and VDE-2026-028
Specific vendor and model information is not yet enumerated in the NVD entry
Refer to the linked CERT@VDE advisories for authoritative product and version lists

Discovery Timeline

2026-09-16 - CVE-2026-27547 published to the National Vulnerability Database (NVD)
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-27547

Vulnerability Analysis

The vulnerability resides in the AJAX handler exposed at /index.php/ajax/get_iodd_menu_info. The handler consumes attacker-controlled input and passes it into an operating system command execution context without adequate sanitization or argument separation. Because the underlying web service runs as root, injected commands inherit full administrative privileges on the device.

Exploitation requires only low-privileged authentication. Both standard user and operator accounts are sufficient, which broadens the attacker population beyond administrators. Once authenticated, the attacker sends a single crafted HTTP request that carries shell metacharacters or command separators in a request parameter processed by the endpoint.

The result is arbitrary command execution as root over the network. This grants the attacker full read and write access to the filesystem, the ability to modify device configuration, credential extraction, and persistence installation.

Root Cause

The root cause is improper neutralization of special elements used in an OS command [CWE-78]. The PHP handler concatenates untrusted input into a shell invocation instead of using parameterized execution APIs or strict allow-list validation.

Attack Vector

The attack vector is network-based over HTTP or HTTPS to the device management interface. The attacker authenticates with valid low-privileged credentials, then issues an HTTP request to /index.php/ajax/get_iodd_menu_info with a payload containing shell control characters. The injected commands run in the web server process context, which executes as root on affected devices.

No verified public exploit code is available in the enriched data. Refer to the CERT@VDE advisories for authoritative technical detail.

Detection Methods for CVE-2026-27547

Indicators of Compromise

HTTP POST or GET requests to /index.php/ajax/get_iodd_menu_info containing shell metacharacters such as ;, |, &, backticks, or $(...) in request parameters
Web server or PHP process spawning unexpected child processes such as /bin/sh, wget, curl, nc, or busybox
Outbound network connections from the device to unfamiliar hosts shortly after requests to the affected endpoint
New or modified files in web root, /tmp, or persistence locations such as init scripts and cron entries

Detection Strategies

Deploy web application firewall or reverse proxy rules that inspect requests to /index.php/ajax/get_iodd_menu_info for command injection patterns
Correlate authentication events for user and operator accounts with subsequent requests to the vulnerable endpoint
Monitor process ancestry on the device to flag shell processes parented by the web server
Alert on outbound traffic from management interfaces that historically only receive inbound connections

Monitoring Recommendations

Forward device web server access logs and authentication logs to a centralized SIEM for retention and correlation
Baseline normal request patterns to the /ajax/ path space and alert on deviations
Track failed and successful logins for low-privileged accounts to identify credential stuffing that precedes exploitation

How to Mitigate CVE-2026-27547

Immediate Actions Required

Restrict network access to the device management interface to trusted administrative networks only
Rotate credentials for all user and operator accounts and enforce strong, unique passwords
Disable or remove unused low-privileged accounts to reduce the exploitable authentication surface
Review web server and authentication logs for prior access to /index.php/ajax/get_iodd_menu_info with suspicious parameters

Patch Information

Refer to the vendor advisories published through CERT@VDE for patched firmware or software versions and upgrade instructions: CERT@VDE Advisory VDE-2026-014, CERT@VDE Advisory VDE-2026-027, and CERT@VDE Advisory VDE-2026-028. Apply the vendor-supplied fixes as soon as they are available for your affected model.

Workarounds

Place the device management interface behind a VPN or jump host and block direct internet exposure
Apply network ACLs on upstream firewalls to permit management traffic only from named administrator workstations
Where supported, use a reverse proxy to block requests to /index.php/ajax/get_iodd_menu_info containing shell metacharacters until a patch is applied
Monitor and rate-limit authentication attempts against the device to slow credential-based access paths

bash

# Example upstream firewall restriction (iptables) limiting management access
iptables -A INPUT -p tcp --dport 443 -s 10.0.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP

# Example NGINX reverse-proxy rule blocking suspicious payloads to the endpoint
location ~ ^/index\.php/ajax/get_iodd_menu_info {
    if ($args ~* "[;&|`$()]") { return 403; }
    proxy_pass https://device.internal;
}