Overview
CVE-2024-39148 describes a critical security vulnerability affecting KerOS versions prior to 5.12. Specifically, the `wmp-agent` service suffers from improper validation of so-called ‘magic URLs’. This flaw allows an unauthenticated, remote attacker to execute arbitrary operating system commands with root privileges, provided the `wmp-agent` service is reachable over the network. While the service is typically protected by a local firewall, misconfigurations or other network exposures could leave systems vulnerable.
Technical Details
The vulnerability stems from the `wmp-agent` service’s failure to properly sanitize and validate input received via specially crafted URLs (the “magic URLs”). By sending a malicious request containing OS commands within these URLs, an attacker can bypass security checks and execute code directly on the underlying operating system with root privileges. The insufficient input validation is the root cause of this critical security flaw.
Further details on the specific “magic URLs” and the method of exploitation are available in the references provided below.
CVSS Analysis
Due to the severity and impact of this vulnerability, one would expect a very high CVSS score. However, the provided information currently lists the CVSS score as N/A. This may be because the assessment is pending or is being performed by a third party. Given the potential for unauthenticated remote root code execution, a score in the Critical range (CVSS v3 score of 9.0-10.0) is highly probable once evaluated.
Specifically, this vulnerability satisfies the following criteria for a high CVSS score:
- Attack Vector: Network (AV:N)
- Attack Complexity: Likely Low (AC:L), depending on network configuration
- Privileges Required: None (PR:N)
- User Interaction: None (UI:N)
- Scope: Changed (S:C) – Code execution impacts the system beyond the vulnerable component.
- Confidentiality Impact: High (C:H)
- Integrity Impact: High (I:H)
- Availability Impact: High (A:H)
Possible Impact
Successful exploitation of CVE-2024-39148 can have devastating consequences:
- Complete System Compromise: An attacker gains full control over the affected KerOS device with root privileges.
- Data Breach: Sensitive data stored on the device can be accessed and exfiltrated.
- Denial of Service (DoS): The attacker can render the device unusable by disrupting its services.
- Botnet Recruitment: Compromised devices can be incorporated into botnets for malicious activities.
- Lateral Movement: An attacker can use the compromised device to gain access to other systems on the same network.
Because the `wmp-agent` is typically used in IoT and gateway devices, the compromise of a KerOS device can have serious repercussions for the entire IoT ecosystem.
Mitigation and Patch Steps
The primary mitigation is to upgrade to KerOS version 5.12 or later. This version contains the necessary fixes to address the vulnerability.
In addition to upgrading, consider the following security best practices:
- Firewall: Ensure the `wmp-agent` service is only accessible from trusted networks or local interfaces. Block external access to the service whenever possible.
- Network Segmentation: Isolate IoT devices running KerOS on a separate network segment to limit the potential impact of a compromise.
- Regular Security Audits: Conduct regular security audits to identify and address potential vulnerabilities.
- Intrusion Detection/Prevention Systems (IDS/IPS): Implement IDS/IPS solutions to detect and prevent exploitation attempts.
Apply the update provided by Kerlink as soon as possible!
References
Kerlink Security Advisories (kerOS5)
BDO Security Advisory for CVE-2024-39148
