CVE-2018-20679 : Exploit Details and Defense Strategies

CVE-2018-20679, published on January 9, 2019, addresses a vulnerability in BusyBox versions prior to 1.30.0. This vulnerability allows a remote attacker to retrieve sensitive information from the stack through a manipulated DHCP message.

Understanding CVE-2018-20679

This CVE entry pertains to a specific vulnerability in BusyBox versions before 1.30.0 that can be exploited by attackers to access sensitive data.

What is CVE-2018-20679?

CVE-2018-20679 is an out-of-bounds read vulnerability in udhcp components of BusyBox, which are utilized by the DHCP server, client, and relay. The issue arises from a lack of proper verification in the udhcp_get_option() function, leading to the exposure of stack information.

The Impact of CVE-2018-20679

The vulnerability in BusyBox versions prior to 1.30.0 can have the following impacts:

Remote attackers can retrieve sensitive information from the stack.
Exploitation can lead to unauthorized access to critical data.

Technical Details of CVE-2018-20679

This section delves into the technical aspects of the CVE-2018-20679 vulnerability.

Vulnerability Description

The vulnerability in BusyBox versions before 1.30.0 is due to an out-of-bounds read in udhcp components, allowing attackers to extract sensitive information from the stack by sending a crafted DHCP message.

Affected Systems and Versions

Affected Systems: BusyBox versions prior to 1.30.0
Affected Components: udhcp components used by the DHCP server, client, and relay

Exploitation Mechanism

The exploitation of this vulnerability involves sending a manipulated DHCP message to the target system, triggering the out-of-bounds read in udhcp components and enabling the retrieval of sensitive data from the stack.

Mitigation and Prevention

To address CVE-2018-20679 and enhance system security, consider the following mitigation strategies:

Immediate Steps to Take

Update BusyBox to version 1.30.0 or later to eliminate the vulnerability.
Monitor network traffic for any suspicious DHCP messages.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks.
Regularly audit and update software components to patch known vulnerabilities.

Patching and Updates

Apply security patches promptly to ensure that systems are protected against known vulnerabilities.