CVE-2025-34187: Ilevia Eve X1 Privilege Escalation Flaw

CVE-2025-34187 Overview

CVE-2025-34187 is a privilege escalation vulnerability affecting Ilevia EVE X1 and X5 Server devices running firmware version 4.7.18.0.eden and earlier. The flaw originates from a misconfiguration in the /etc/sudoers file that permits passwordless sudo execution of specific Bash scripts. When these scripts are writable by web-facing users or reachable through command injection, attackers can overwrite them with malicious payloads. Subsequent execution under sudo grants full root privileges on the device, leading to complete system compromise. The vulnerability is classified under CWE-78, OS Command Injection.

Critical Impact
Remote attackers can achieve root-level code execution on Ilevia EVE X1/X5 home automation servers without authentication, enabling full takeover of building control systems.

Affected Products

Ilevia EVE X1 Server firmware version ≤ 4.7.18.0.eden
Ilevia EVE X5 Server firmware version ≤ 4.7.18.0.eden
Ilevia EVE X1 Server hardware appliance

Discovery Timeline

2025-09-16 - CVE-2025-34187 published to the National Vulnerability Database
2025-09-25 - Last updated in NVD database

Technical Details for CVE-2025-34187

Vulnerability Analysis

The Ilevia EVE X1/X5 Server is a building automation controller exposing web management interfaces. The device ships with a sudoers policy granting the low-privileged web service account NOPASSWD permission to invoke designated Bash scripts as root. These scripts reside in filesystem locations writable by the same low-privileged account that serves the web application.

This configuration violates the principle of least privilege. An attacker who reaches the web tier through command injection, file upload, or any code execution primitive can overwrite the trusted script with arbitrary shell commands. Invoking the script through the permitted sudo rule then executes the attacker-controlled payload as root.

The vulnerability has an EPSS probability of 1.399% at the 80.6 percentile, indicating elevated likelihood of exploitation relative to most published CVEs. Public technical reports are available from VulnCheck and Zero Science Lab.

Root Cause

The root cause is an insecure sudoers policy combined with weak filesystem permissions on the privileged scripts. The two issues compound: passwordless sudo removes authentication, while writable script paths allow content substitution. Either control alone would prevent exploitation.

Attack Vector

The attack proceeds over the network against the device web interface. An attacker first obtains code execution in the web context through command injection or by leveraging the writable script path directly. The attacker then writes a malicious payload into one of the scripts listed in sudoers and invokes that script using sudo. The system executes the replaced contents with root privileges, yielding a reverse root shell or persistent backdoor.

No verified proof-of-concept code is published in the referenced advisories. Public reporting describes the chain in prose, and a reverse root shell technique is documented in the VulnCheck advisory.

Detection Methods for CVE-2025-34187

Indicators of Compromise

Unexpected modifications to Bash scripts referenced in the device /etc/sudoers file or sudoers.d directory
Outbound network connections from the EVE X1/X5 device to unfamiliar IP addresses, consistent with reverse shell activity
New cron jobs, SSH keys, or system users created on the device after web-tier activity
Web server access logs containing payloads with shell metacharacters such as ;, |, `, or $( targeting CGI endpoints

Detection Strategies

Monitor file integrity on all scripts referenced by sudoers rules and alert on any write operation by non-root accounts
Inspect auth.log and secure logs for sudo invocations originating from the web service user identity
Baseline normal outbound traffic from building automation devices and flag deviations such as long-lived TCP sessions to external hosts

Monitoring Recommendations

Capture process telemetry on the device when feasible and correlate web request timing with sudo executions
Forward device syslog to a centralized SIEM for cross-host correlation and retention
Review network segmentation logs to confirm the EVE controller cannot initiate connections to arbitrary internet hosts

How to Mitigate CVE-2025-34187

Immediate Actions Required

Restrict network access to EVE X1/X5 management interfaces using firewall rules that permit only trusted management workstations
Audit the /etc/sudoers file and remove NOPASSWD entries that reference scripts located in writable directories
Reset the device to a known-good state and rotate any credentials or keys that may have been exposed if compromise is suspected

Patch Information

No vendor advisory or fixed firmware version is referenced in the NVD entry at the time of publication. Operators should contact Ilevia directly through the Ilevia company website for remediation guidance and monitor for firmware releases beyond 4.7.18.0.eden.

Workarounds

Remove or comment out passwordless sudo rules referencing scripts in user-writable paths until a vendor patch is released
Tighten filesystem permissions so privileged scripts are owned by root with mode 0755 and are not writable by the web service account
Place the device behind a VPN or management VLAN to prevent direct network exposure to untrusted clients
Disable any unused web endpoints on the device that could serve as command injection entry points

bash

# Configuration example: harden sudoers and script permissions
# Remove writable bits on privileged scripts referenced by sudoers
chown root:root /path/to/privileged_script.sh
chmod 0755 /path/to/privileged_script.sh

# Review and edit sudoers safely
visudo
# Remove or replace lines such as:
#   webuser ALL=(ALL) NOPASSWD: /path/to/privileged_script.sh
# With an explicit allowlist that points to root-owned, non-writable scripts only.