CVE-2019-20104 : Exploit Details and Defense Strategies

Atlassian Crowd before 3.6.2 and from 3.7.0 to 3.7.1 is vulnerable to a Denial of Service attack through an XML Entity Expansion vulnerability.

Understanding CVE-2019-20104

Remote attackers can exploit this vulnerability to target the OpenID client application in Atlassian Crowd.

What is CVE-2019-20104?

The vulnerability allows for a Denial of Service attack via XML Entity Expansion in the OpenID client application of Atlassian Crowd.

The Impact of CVE-2019-20104

Remote attackers can launch a Denial of Service attack against the OpenID client application in Atlassian Crowd.
The affected versions are prior to 3.6.2 and from 3.7.0 to 3.7.1.

Technical Details of CVE-2019-20104

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The OpenID client application in Atlassian Crowd before version 3.6.2, and from version 3.7.0 before 3.7.1 allows remote attackers to perform a Denial of Service attack via an XML Entity Expansion vulnerability.

Affected Systems and Versions

Product: Crowd
Vendor: Atlassian
Affected Versions:
Versions prior to 3.6.2
Versions from 3.7.0 to 3.7.1

Exploitation Mechanism

The vulnerability can be exploited through an XML Entity Expansion vulnerability.

Mitigation and Prevention

Steps to address and prevent the CVE-2019-20104 vulnerability:

Immediate Steps to Take

Upgrade Atlassian Crowd to version 3.6.2 or higher.
Implement network security measures to restrict access to vulnerable components.

Long-Term Security Practices

Regularly update and patch software to mitigate known vulnerabilities.
Conduct security assessments and audits to identify and address potential weaknesses.

Patching and Updates

Apply security patches provided by Atlassian promptly to address the vulnerability.