CVE-2021-39118 : Security Advisory and Response

This CVE-2021-39118 report pertains to a vulnerability found in Atlassian Jira Server and Data Center that enables remote attackers to access user information.

Understanding CVE-2021-39118

CVE-2021-39118 involves a user enumeration vulnerability in Atlassian Jira Server and Data Center, allowing malicious actors to obtain user details.

What is CVE-2021-39118?

The flaw in Atlassian Jira Server and Data Center lets attackers discover usernames and full names of users by exploiting the /rest/api/1.0/render endpoint before version 8.19.0.

The Impact of CVE-2021-39118

The vulnerability can lead to unauthorized access to sensitive user information, posing a risk to data confidentiality and potentially enabling further attacks.

Technical Details of CVE-2021-39118

This section delves into the specifics of the vulnerability in Atlassian Jira Server and Data Center.

Vulnerability Description

The flaw permits remote attackers to enumerate user details, including usernames and full names, through the /rest/api/1.0/render endpoint in affected versions prior to 8.19.0.

Affected Systems and Versions

Product: Jira Server
Vendor: Atlassian
Versions Affected: < 8.19.0 (custom)
Product: Jira Data Center
Vendor: Atlassian
Versions Affected: < 8.19.0 (custom)

Exploitation Mechanism

Attackers can exploit the enumeration vulnerability in the /rest/api/1.0/render endpoint to access user information in vulnerable versions.

Mitigation and Prevention

Ways to address and prevent the CVE-2021-39118 vulnerability in Atlassian Jira Server and Data Center.

Immediate Steps to Take

Upgrade Atlassian Jira Server and Data Center to version 8.19.0 or newer to mitigate the vulnerability.
Monitor user access and suspicious activities related to user enumeration.

Long-Term Security Practices

Regularly update software and apply security patches promptly to prevent exposure to known vulnerabilities.
Implement access controls and authentication mechanisms to restrict unauthorized access to user information.

Patching and Updates

Atlassian has released version 8.19.0 to address the vulnerability; ensure timely installation of this update to enhance system security.