CVE-2019-5138 : Security Advisory and Response

The Moxa AWK-3131A firmware version 1.13 contains a critical vulnerability that allows for command injection, potentially leading to remote control of the affected device.

Understanding CVE-2019-5138

This CVE involves a vulnerability in the encrypted diagnostic script functionality of the Moxa AWK-3131A firmware version 1.13.

What is CVE-2019-5138?

The vulnerability allows for the execution of arbitrary busybox commands by manipulating a diagnostic script file.
Attackers can exploit this flaw to gain remote control over the device.
The attacker needs to send a diagnostic request while authenticated as a user with low privileges to trigger the vulnerability.

The Impact of CVE-2019-5138

CVSS Base Score: 9.9 (Critical)
Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: High
Scope: Changed
User Interaction: None

Technical Details of CVE-2019-5138

The following technical details provide insight into the vulnerability.

Vulnerability Description

The vulnerability is categorized as CWE-78: Improper Neutralization of Special Elements used in an OS Command (OS Command Injection).

Affected Systems and Versions

Product: Moxa
Vendor: n/a
Version: Moxa AWK-3131A Firmware version 1.13

Exploitation Mechanism

Attackers can exploit the vulnerability by manipulating a diagnostic script file to execute arbitrary busybox commands.

Mitigation and Prevention

Taking immediate steps and implementing long-term security practices are crucial to mitigate the risks associated with CVE-2019-5138.

Immediate Steps to Take

Update the firmware to a patched version that addresses the vulnerability.
Restrict network access to the affected device.
Monitor network traffic for any suspicious activity.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Implement strong authentication mechanisms and access controls.
Conduct regular security audits and assessments.

Patching and Updates

Apply patches provided by the vendor to fix the vulnerability and enhance the security of the device.