CVE-2021-43943 : Security Advisory and Response

A Cross-Site Scripting (XSS) vulnerability in Atlassian Jira Service Management Server and Data Center versions before 4.21.0 allows attackers with admin privileges to inject malicious code.

Understanding CVE-2021-43943

This CVE pertains to a Stored XSS vulnerability in Atlassian Jira products.

What is CVE-2021-43943?

The vulnerability enables attackers with admin access to execute arbitrary HTML or JavaScript through a specific field.

The Impact of CVE-2021-43943

Attackers can inject malicious code through the "Object Schema" field, posing a risk of unauthorized data access or system manipulation.

Technical Details of CVE-2021-43943

This section outlines the technical aspects of the CVE.

Vulnerability Description

Type: Stored XSS (SXSS)
Vector: Injection of arbitrary HTML or JavaScript

Affected Systems and Versions

Products: Jira Service Management Server, Jira Service Management Data Center
Versions Affected: < 4.21.0
Custom versions unspecified

Exploitation Mechanism

Attackers with admin privileges exploit the "Object Schema" field in /secure/admin/InsightDefaultCustomFieldConfig.jspa to execute XSS attacks.

Mitigation and Prevention

Preventive measures and action steps for CVE-2021-43943.

Immediate Steps to Take

Upgrade affected versions to 4.21.0 or above.
Implement input validation to block malicious scripts.
Monitor and restrict admin access to critical areas.

Long-Term Security Practices

Regular security training for admin users.
Conduct periodic security audits and code reviews.
Stay informed about security patches and updates.

Patching and Updates

Apply security patches released by Atlassian promptly.
Keep Jira Service Management up to date with the latest stable version.