CVE-2017-8415 : What You Need to Know

A vulnerability was identified on D-Link DCS-1100 and DCS-1130 devices where a hardcoded hash is used for authentication, making it impossible for users to change their passwords due to the read-only nature of the filesystem.

Understanding CVE-2017-8415

This CVE describes a security issue affecting D-Link DCS-1100 and DCS-1130 devices.

What is CVE-2017-8415?

The vulnerability involves the use of a hardcoded hash in the /etc/shadow file for user authentication on D-Link DCS-1100 and DCS-1130 devices.

The Impact of CVE-2017-8415

The vulnerability allows unauthorized users to potentially gain access to the devices using the hardcoded hash, compromising the security of the system.

Technical Details of CVE-2017-8415

This section provides more technical insights into the vulnerability.

Vulnerability Description

The devices use a customized telnet daemon that retrieves passwords from the shadow file using specific memory addresses.
A crypt operation is performed on the user's password, and a strcmp function is used to verify the password.
The /etc/shadow file is stored in a read-only filesystem, preventing users from changing their passwords.

Affected Systems and Versions

Affected devices: D-Link DCS-1100 and DCS-1130
All versions of the devices are impacted by this vulnerability.

Exploitation Mechanism

Unauthorized users can exploit the hardcoded hash in the /etc/shadow file to gain access to the devices.

Mitigation and Prevention

Protecting against and addressing the CVE-2017-8415 vulnerability.

Immediate Steps to Take

Disable telnet services on the affected devices if possible.
Implement strong firewall rules to restrict unauthorized access.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Use strong, unique passwords for device authentication.
Consider implementing multi-factor authentication for enhanced security.

Patching and Updates

Check for firmware updates from D-Link to address the hardcoded hash issue.
Apply patches provided by the vendor to secure the devices against potential exploits.