CVE-2019-20397 : Vulnerability Insights and Analysis

CVE-2019-20397 is a vulnerability found in the function yyparse() in libyang before version 1.0-r1. This vulnerability involves a double-free issue that can be exploited when an organization field is not properly terminated. If applications use libyang to parse yang files from untrusted sources, they may be at risk. The exploitation of this flaw could result in a system crash or the execution of malicious code.

Understanding CVE-2019-20397

This section provides insights into the nature and impact of CVE-2019-20397.

What is CVE-2019-20397?

The vulnerability in CVE-2019-20397 arises from a double-free vulnerability in the yyparse() function within libyang before version 1.0-r1. Improper termination of an organization field can trigger this vulnerability, making systems susceptible to exploitation.

The Impact of CVE-2019-20397

Exploiting CVE-2019-20397 could lead to severe consequences, including system crashes and the potential execution of malicious code. Organizations using libyang to parse yang files from untrusted sources are particularly at risk.

Technical Details of CVE-2019-20397

This section delves into the technical aspects of CVE-2019-20397.

Vulnerability Description

The vulnerability in yyparse() in libyang before version 1.0-r1 is a double-free vulnerability that can be triggered by improper termination of an organization field.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Affected Versions: All versions are affected.

Exploitation Mechanism

Exploiting this vulnerability involves manipulating the termination of an organization field improperly, which triggers the double-free issue in the yyparse() function.

Mitigation and Prevention

This section outlines steps to mitigate and prevent exploitation of CVE-2019-20397.

Immediate Steps to Take

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

Long-Term Security Practices

Regularly update software and libraries to the latest versions to address known vulnerabilities.
Implement code reviews and security testing to identify and mitigate potential vulnerabilities.

Patching and Updates

Apply patches provided by libyang promptly to address the double-free vulnerability in yyparse().