CVE-2019-20198 : Security Advisory and Response

A vulnerability in ezXML versions 0.8.3 through 0.8.6 allows for excessive stack usage due to mishandling of recursion in the ezxml_ent_ok() function.

Understanding CVE-2019-20198

This CVE identifies a flaw in ezXML that can be exploited to cause stack consumption when processing a manipulated XML file.

What is CVE-2019-20198?

The issue arises from the incorrect handling of recursion in the ezxml_ent_ok() function, leading to excessive stack usage during the processing of a specifically crafted XML file.

The Impact of CVE-2019-20198

The vulnerability could be exploited by an attacker to cause a denial of service (DoS) condition by consuming excessive stack resources on the affected system.

Technical Details of CVE-2019-20198

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The ezXML versions 0.8.3 through 0.8.6 mishandle recursion in the ezxml_ent_ok() function, resulting in stack consumption when processing a manipulated XML file.

Affected Systems and Versions

Affected Versions: 0.8.3 through 0.8.6
Systems using ezXML within this version range are vulnerable to the excessive stack usage issue.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting a malicious XML file that triggers the mishandling of recursion in the ezxml_ent_ok() function, leading to stack consumption.

Mitigation and Prevention

Protecting systems from CVE-2019-20198 involves taking immediate steps and implementing long-term security practices.

Immediate Steps to Take

Update ezXML to a patched version that addresses the recursion mishandling issue.
Monitor system resources for any signs of excessive stack usage that could indicate a potential exploit.

Long-Term Security Practices

Regularly update software and libraries to ensure that known vulnerabilities are patched promptly.
Conduct security assessments and code reviews to identify and mitigate similar issues in other parts of the system.

Patching and Updates

Apply patches provided by ezXML to fix the recursion mishandling in the ezxml_ent_ok() function.
Stay informed about security updates and advisories related to ezXML to address any future vulnerabilities.