CVE-2020-7469 : Exploit Details and Defense Strategies

In FreeBSD 12.2-STABLE before r367402, 11.4-STABLE before r368202, 12.2-RELEASE before p1, 12.1-RELEASE before p11, and 11.4-RELEASE before p5, a vulnerability exists that could lead to a use-after-free scenario due to improper handling of routing options in the network stack.

Understanding CVE-2020-7469

This CVE entry describes a specific vulnerability in FreeBSD versions that could potentially be exploited to trigger a use-after-free condition.

What is CVE-2020-7469?

CVE-2020-7469 is a vulnerability in FreeBSD versions that mishandles routing options, leading to a use-after-free scenario in the network stack.

The Impact of CVE-2020-7469

The vulnerability could allow an attacker to exploit the use-after-free condition, potentially leading to a denial of service or arbitrary code execution.

Technical Details of CVE-2020-7469

This section provides more technical insights into the vulnerability.

Vulnerability Description

The issue arises from the handler for a routing option caching a pointer into the packet buffer holding the ICMPv6 message. Subsequent processing of options may free the packet buffer, rendering the cached pointer invalid, which could be later dereferenced by the network stack.

Affected Systems and Versions

FreeBSD 12.2-RELEASE before p1
FreeBSD 12.1-RELEASE before p11
FreeBSD 11.4-RELEASE before p5

Exploitation Mechanism

The vulnerability can be exploited by manipulating routing options in a way that triggers the use-after-free condition in the network stack.

Mitigation and Prevention

Protecting systems from CVE-2020-7469 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the necessary patches provided by FreeBSD to address the vulnerability.
Monitor security advisories for updates and apply them promptly.

Long-Term Security Practices

Regularly update and patch FreeBSD systems to mitigate potential vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Ensure that FreeBSD systems are regularly updated with the latest security patches to prevent exploitation of known vulnerabilities.