CVE-2026-27548 Overview
CVE-2026-27548 is a command injection vulnerability [CWE-78] affecting the /index.php/ajax/get_iodd_port_info endpoint of an industrial device web interface. A low-privileged remote attacker holding user or operator credentials can inject operating system commands into the endpoint. The injected commands execute with root privileges on the underlying device.
The issue 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. The vulnerability affects confidentiality, integrity, and availability of the target device.
Critical Impact
Authenticated attackers with the lowest available role can achieve full root-level code execution on affected devices over the network.
Affected Products
- Devices exposing the /index.php/ajax/get_iodd_port_info PHP endpoint covered by CERT@VDE advisory VDE-2026-014
- Devices covered by CERT@VDE advisory VDE-2026-027
- Devices covered by CERT@VDE advisory VDE-2026-028
Discovery Timeline
- 2026-09-16 - CVE-2026-27548 published to NVD
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-27548
Vulnerability Analysis
The vulnerability is a classic OS command injection flaw in a web-facing PHP endpoint on an embedded device. The endpoint /index.php/ajax/get_iodd_port_info accepts request parameters that are passed to an operating system shell without adequate sanitization or argument separation.
Because the web application runs with root privileges on the device, any injected shell metacharacters or additional commands are executed as root. This transforms a low-privileged authenticated session into full device compromise, including firmware modification, credential theft, and lateral movement into the operational technology (OT) network.
The CWE-78 classification indicates improper neutralization of special elements used in an OS command. Exploitation requires only user or operator credentials, which are the lowest privilege tiers on the affected platform.
Root Cause
The root cause is unsafe construction of a shell command string using untrusted input received by the get_iodd_port_info AJAX handler. Input validation and safe process-execution APIs are not applied before the command is passed to a shell interpreter, allowing metacharacters such as ;, |, &, and backticks to break out of the intended command context.
Attack Vector
An attacker first authenticates to the web interface using any valid user or operator account, including default or shared credentials common in industrial deployments. The attacker then submits a crafted HTTP request to the /index.php/ajax/get_iodd_port_info endpoint with malicious payload data in a vulnerable parameter. The server concatenates the payload into a shell command, and the injected commands execute as root.
No user interaction is required beyond the initial authentication. Refer to the CERT@VDE advisory VDE-2026-014 for endpoint-specific technical detail.
Stop Remote Code Execution Before It Runs
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Stop Exploit AttemptsDetection Methods for CVE-2026-27548
Indicators of Compromise
- HTTP POST or GET requests to /index.php/ajax/get_iodd_port_info containing shell metacharacters such as ;, |, &, $(, or backticks in parameter values
- Unexpected child processes spawned by the web server process (for example, sh, bash, wget, curl, nc) running as root
- New or modified files under web-writable directories, /tmp, or system binary paths on the affected device
- Outbound connections initiated from the device to unfamiliar IP addresses shortly after web requests to the vulnerable endpoint
Detection Strategies
- Inspect web server access logs for requests to get_iodd_port_info that include URL-encoded shell characters (%3B, %7C, %26, %24%28)
- Correlate authenticated low-privilege sessions with subsequent root-level process activity on the device
- Deploy network intrusion detection signatures that match command injection patterns targeting the vulnerable endpoint path
Monitoring Recommendations
- Forward device web server and syslog output to a centralized logging platform for retention and correlation
- Alert on any successful authentication to the device followed by anomalous outbound network traffic
- Baseline normal request patterns to /index.php/ajax/ endpoints and flag deviations in parameter structure or size
How to Mitigate CVE-2026-27548
Immediate Actions Required
- Restrict network access to the device management interface using firewall rules, VLAN segmentation, or a jump host, and block access from untrusted networks
- Rotate all user and operator credentials on affected devices, and remove any shared or default accounts
- Review web server logs for prior exploitation attempts against /index.php/ajax/get_iodd_port_info
- Apply vendor firmware updates as soon as they are made available through the referenced CERT@VDE advisories
Patch Information
Refer to the vendor coordination advisories for patch availability and firmware versions: CERT@VDE Advisory VDE-2026-014, CERT@VDE Advisory VDE-2026-027, and CERT@VDE Advisory VDE-2026-028. Apply the fixed firmware version listed in each advisory that matches your device model.
Workarounds
- Place the device behind a network firewall that restricts inbound HTTP/HTTPS access to a small set of trusted management workstations
- Disable or remove low-privilege user and operator accounts that are not strictly required for operations
- Monitor and log all web management activity, and terminate sessions from unexpected source addresses
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
