CVE-2019-6258 : Security Advisory and Response

Devices belonging to the D-Link DIR-822 Rev.Bx model, running firmware version v.202KRb06 or earlier, are susceptible to a buffer overflow vulnerability when handling HNAP protocol messages.

Understanding CVE-2019-6258

This CVE identifies a buffer overflow vulnerability in D-Link DIR-822 Rev.Bx devices running specific firmware versions.

What is CVE-2019-6258?

The vulnerability arises from mishandling excessively long MacAddress data in a specific HNAP protocol message.

The Impact of CVE-2019-6258

Attackers can exploit this vulnerability by sending a crafted message to trigger a buffer overflow in the /usr/sbin/udhcpd component.
Successful exploitation could lead to arbitrary code execution or denial of service.

Technical Details of CVE-2019-6258

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows attackers to execute arbitrary code or cause a denial of service by sending a malicious HNAP protocol message with long MacAddress data.

Affected Systems and Versions

Devices: D-Link DIR-822 Rev.Bx model
Firmware: v.202KRb06 and earlier

Exploitation Mechanism

Exploitation involves sending a crafted message to the /HNAP1/SetClientInfo endpoint with excessively long MacAddress data.
The vulnerability is triggered during the reading process of the /var/servd/LAN-1-udhcpd.conf file.

Mitigation and Prevention

Protecting systems from CVE-2019-6258 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update the firmware of D-Link DIR-822 Rev.Bx devices to the latest version that addresses the vulnerability.
Implement network segmentation to limit the impact of potential attacks.
Monitor network traffic for any suspicious activity.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Conduct security assessments and penetration testing to identify and address weaknesses.
Educate users on safe browsing habits and the importance of cybersecurity.

Patching and Updates

D-Link has released patches to address the vulnerability in affected firmware versions.
Regularly check for updates and apply them promptly to ensure system security.