Overview
CVE-2024-32388 is a medium severity vulnerability affecting Kerlink devices running KerOS prior to version 5.12. A firewall misconfiguration allows attackers to bypass security measures by sending specially crafted UDP packets, potentially granting unauthorized access to UDP-based services that should be protected by the firewall.
Technical Details
The vulnerability stems from an improperly configured firewall rule set within KerOS. Specifically, the firewall fails to adequately filter UDP packets based on certain criteria, allowing malicious actors to craft packets that are incorrectly accepted by the device. This leads to the bypass of intended access restrictions and opens the door to potentially harmful activities.
Exploitation requires an attacker to send specially crafted UDP packets to the vulnerable Kerlink device.
CVSS Analysis
The Common Vulnerability Scoring System (CVSS) assigns a score of 5.3 to CVE-2024-32388. This score reflects the following characteristics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Confidentiality Impact: None
- Integrity Impact: Low
- Availability Impact: None
While the overall score is medium, the low attack complexity and lack of required privileges make this vulnerability relatively easy to exploit.
Possible Impact
Successful exploitation of CVE-2024-32388 could lead to the following:
- Unauthorized access to UDP-based services running on the Kerlink device.
- Potential for further exploitation depending on the exposed services.
- Data exfiltration if exposed services allow it.
- Denial-of-service attacks by overwhelming the exposed services.
Mitigation or Patch Steps
The recommended mitigation is to update KerOS to version 5.12 or later. This update includes a corrected firewall configuration that addresses the vulnerability. Users are strongly advised to apply the update as soon as possible.
To update:
- Download the latest KerOS firmware from Kerlink’s official website.
- Follow the instructions provided in the Kerlink documentation for upgrading the firmware.
- Verify the installation by checking the KerOS version after the update.
