CVE-2018-19989 : Exploit Details and Defense Strategies

A vulnerability in the uplink parameter of the /HNAP1/SetQoSSettings message affects D-Link DIR-822 Rev.B 202KRb06 and DIR-822 Rev.C 3.10B06 devices.

Understanding CVE-2018-19989

This CVE involves a security flaw in the handling of the uplink parameter in specific D-Link router models.

What is CVE-2018-19989?

The vulnerability lies in how the uplink parameter is processed within certain PHP source code files, potentially allowing for unauthorized access.

The Impact of CVE-2018-19989

The vulnerability could be exploited by crafting a malicious XML message to execute arbitrary commands on affected devices, posing a significant security risk.

Technical Details of CVE-2018-19989

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The uplink parameter in the /HNAP1/SetQoSSettings message is not properly validated, leading to potential command injection attacks.

Affected Systems and Versions

D-Link DIR-822 Rev.B 202KRb06
D-Link DIR-822 Rev.C 3.10B06

Exploitation Mechanism

The uplink parameter is stored in internal configuration memory without regex validation.
Data from the uplink parameter is used with the tc command without proper validation, creating an exploitable scenario.

Mitigation and Prevention

Protecting systems from CVE-2018-19989 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply vendor-supplied patches promptly.
Monitor network traffic for any suspicious activity.
Restrict access to vulnerable services.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Implement network segmentation to limit the impact of potential breaches.

Patching and Updates

Check for firmware updates from D-Link and apply them as soon as they are available.