CVE-2019-20394 : Exploit Details and Defense Strategies

CVE-2019-20394 is a vulnerability found in Libyang versions prior to v1.0-r3, involving a double-free vulnerability within the yyparse() function. This flaw can lead to a crash or potential code execution when a type statement is used in a notification statement.

Understanding CVE-2019-20394

Libyang versions prior to v1.0-r3 are affected by a critical security issue that could be exploited to cause a crash or execute arbitrary code.

What is CVE-2019-20394?

The vulnerability in CVE-2019-20394 occurs in the yyparse() function of Libyang when a type statement is employed in a notification statement, potentially allowing an attacker to crash the application or execute malicious code.

The Impact of CVE-2019-20394

Exploitation of this vulnerability could lead to a crash of the application or enable an attacker to execute arbitrary code, posing a significant risk to systems utilizing Libyang for parsing untrusted yang files.

Technical Details of CVE-2019-20394

Libyang versions prior to v1.0-r3 are susceptible to a double-free vulnerability within the yyparse() function.

Vulnerability Description

The vulnerability arises when a type statement is used in a notification statement, potentially leading to a crash or code execution.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions prior to v1.0-r3 are affected.

Exploitation Mechanism

The vulnerability can be exploited by utilizing a type statement in a notification statement, allowing an attacker to potentially crash the application or execute malicious code.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of CVE-2019-20394.

Immediate Steps to Take

Update Libyang to version v1.0-r3 or later to mitigate the vulnerability.
Avoid parsing untrusted yang files until the software is patched.

Long-Term Security Practices

Regularly update software and libraries to the latest versions to address known vulnerabilities.
Implement secure coding practices to minimize the risk of similar vulnerabilities.

Patching and Updates

Apply the security update provided by Libyang to patch the vulnerability and enhance system security.