CVE-2019-20395 : What You Need to Know

CVE-2019-20395 is a vulnerability found in libyang prior to version 1.0-r1, leading to a stack consumption issue due to a self-referential union type that includes leafrefs. This vulnerability can cause crashes in applications that analyze yang files from untrusted sources.

Understanding CVE-2019-20395

This section provides insights into the nature and impact of CVE-2019-20395.

What is CVE-2019-20395?

CVE-2019-20395 is a stack consumption problem present in libyang versions before v1.0-r1, arising from a self-referential union type with leafrefs. This issue can result in application crashes when processing yang files from untrusted origins.

The Impact of CVE-2019-20395

The vulnerability in libyang can lead to denial of service (DoS) attacks and potential system instability. Attackers could exploit this flaw to crash applications that rely on libyang for yang file analysis.

Technical Details of CVE-2019-20395

Explore the technical aspects of CVE-2019-20395 to understand its implications.

Vulnerability Description

The vulnerability stems from a stack consumption problem in libyang versions preceding v1.0-r1, caused by a self-referential union type containing leafrefs. This design flaw can be exploited to disrupt application functionality.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Affected Versions: All versions prior to libyang v1.0-r1

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting malicious yang files and tricking applications into processing them. The presence of self-referential union types with leafrefs triggers the stack consumption issue, leading to crashes.

Mitigation and Prevention

Learn how to mitigate the risks associated with CVE-2019-20395.

Immediate Steps to Take

Update libyang to version 1.0-r1 or later to patch the vulnerability.
Avoid processing yang files from untrusted sources until the patch is applied.

Long-Term Security Practices

Regularly update software components to ensure the latest security fixes are in place.
Implement input validation mechanisms to filter out potentially malicious yang files.

Patching and Updates

Apply the security update provided by libyang to address the stack consumption problem and enhance system stability.