CVE-2021-28905 : What You Need to Know

In function lys_node_free() in libyang version 1.0.225 and below, a vulnerability exists where it asserts that the value of node->module cannot be NULL. However, in specific scenarios, node->module can indeed be null, leading to a reachable assertion (CWE-617).

Understanding CVE-2021-28905

This section provides insights into the nature and impact of the CVE-2021-28905 vulnerability.

What is CVE-2021-28905?

CVE-2021-28905 is a vulnerability in the libyang library where an incorrect assertion can be triggered due to a null value of node->module in certain cases.

The Impact of CVE-2021-28905

The impact of this vulnerability is that it may allow an attacker to exploit the reachable assertion, potentially leading to security breaches or service disruption.

Technical Details of CVE-2021-28905

Here, you will find detailed technical information regarding the CVE-2021-28905 vulnerability.

Vulnerability Description

The vulnerability stems from the function lys_node_free() in libyang version 1.0.225 and earlier, which incorrectly assumes that the node->module value cannot be NULL.

Affected Systems and Versions

All versions of libyang up to v1.0.225 are affected by this vulnerability.

Exploitation Mechanism

By manipulating specific scenarios where node->module is null, an attacker can trigger the reachable assertion, exploiting the vulnerability.

Mitigation and Prevention

This section outlines steps to mitigate and prevent the exploitation of CVE-2021-28905.

Immediate Steps to Take

Users are advised to update libyang to a version that contains a patch for CVE-2021-28905 and follow security best practices.

Long-Term Security Practices

Implementing secure coding practices and regular security audits can help mitigate the risk of similar vulnerabilities in the future.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by libyang to address CVE-2021-28905.