CVE-2020-7464 : Exploit Details and Defense Strategies

In FreeBSD 12.2-STABLE before r365730, 11.4-STABLE before r365738, 12.1-RELEASE before p10, 11.4-RELEASE before p4, and 11.3-RELEASE before p14, a programming error in the ure(4) device driver caused some Realtek USB Ethernet interfaces to incorrectly report packets with more than 2048 bytes in a single USB transfer as having a length of only 2048 bytes. This vulnerability can be exploited by an adversary to inject packets across security boundaries such as VLANs due to misinterpretation of packet payloads.

Understanding CVE-2020-7464

This section provides insights into the impact and technical details of the CVE.

What is CVE-2020-7464?

CVE-2020-7464 is a vulnerability in FreeBSD versions mentioned above that allows an attacker to inject packets across security boundaries by exploiting a programming error in the ure(4) device driver.

The Impact of CVE-2020-7464

The vulnerability enables an adversary to cause the driver to misinterpret part of a large packet's payload as a separate packet, leading to packet injection across security boundaries like VLANs.

Technical Details of CVE-2020-7464

This section delves into the technical aspects of the CVE.

Vulnerability Description

The programming error in the ure(4) device driver causes Realtek USB Ethernet interfaces to incorrectly report packet lengths, allowing an attacker to inject packets across security boundaries.

Affected Systems and Versions

FreeBSD 12.1-RELEASE before p10
FreeBSD 11.4-RELEASE before p4
FreeBSD 11.3-RELEASE before p14

Exploitation Mechanism

The vulnerability arises from the driver misinterpreting part of a large packet's payload as a separate packet, enabling an attacker to inject packets across security boundaries.

Mitigation and Prevention

Protecting systems from CVE-2020-7464 involves immediate steps and long-term security practices.

Immediate Steps to Take

Apply the necessary patches provided by FreeBSD to address the vulnerability.
Monitor network traffic for any signs of packet injection.

Long-Term Security Practices

Regularly update and patch FreeBSD systems to prevent known vulnerabilities.
Implement network segmentation to limit the impact of potential packet injection attacks.
Conduct security audits and assessments to identify and mitigate similar vulnerabilities.
Educate users and administrators on secure network practices.

Patching and Updates

Ensure timely installation of patches and updates released by FreeBSD to mitigate the CVE-2020-7464 vulnerability.