CVE-2023-22515 - Uncovering a Critical Vulnerability in Atlassian Confluence Data Center and Server Instances

Recently, Atlassian has been notified by several customers of a potential breach in their Confluence Data Center and Server instances. This vulnerability, identified as CVE-2023-22515, allows external attackers to potentially exploit a previously unknown flaw, creating unauthorized Confluence administrator accounts and gaining unrestricted access to the affected Confluence instances. It is crucial to emphasize that Atlassian Cloud sites remain unaffected by this vulnerability, and this issue is solely related to Confluence Data Center and Server instances.

In this post, we will delve deeper into this flaw, discuss its potential impact, present a sample code snippet indicative of the vulnerability, and provide helpful links to help you secure your Confluence environment.

Code Snippet

The vulnerability’s root cause appears to be a failure to validate and sanitize certain inputs in the creation of administrator accounts. Here is a sample code snippet illustrating the potential issue:

public boolean createAdmin(String username, String email, String password) {
    if (userExists(username)) {
        return false;
    }
    
    // Vulnerable code here - lack of proper input validation and sanitation
    User admin = new User(username, email, password, UserRole.ADMIN);
    userStore.saveUser(admin);
    
    return true;
}

By not validating and sanitizing user inputs, attackers could potentially input malicious data that would grant them administrator-level access to the affected Confluence instance.

Exploit Details

The attackers appear to have purposely targeted publicly accessible Confluence Data Center and Server instances, exploiting the vulnerability by sending crafted network packets to the affected instances. With the right set of crafted network packets and knowing the vulnerabilities to exploit, attackers can essentially create unauthorized Confluence administrator accounts, granting them complete access to Confluence instances.

Attacker crafts and sends a network packet containing malicious data.

2. Confluence instance processes the packet, unknowingly creating the unauthorized administrator account.
3. Attacker logs in to the newly created administrator account, providing complete access to the Confluence instance.

Original References and Advisory Links

To gain a deeper understanding of this vulnerability and obtain guidance for securing your Confluence environment, please review the following official Atlassian resources:

1. CVE-2023-22515 Security Advisory – Comprehensive information on the vulnerability along with steps to safeguard your Confluence Data Center and Server instances.
2. Atlassian Security Updates – Stay up-to-date with the latest security updates and announcements from Atlassian.

Conclusion

It is clear that CVE-2023-22515 poses a significant risk to the Confluence Data Center and Server instances, demanding immediate attention. By implementing the recommended security measures and staying informed about Atlassian's security updates, you can help to protect your Confluence environment and efficiently mitigate any risks associated with this vulnerability.

Remember, Atlassian Cloud sites are not affected by this vulnerability: if your Confluence site is accessed via an atlassian.net domain, it is safe as it is hosted by Atlassian and not susceptible to this particular issue.

Timeline

Published on: 10/04/2023 14:15:00 UTC
Last modified on: 10/10/2023 19:22:00 UTC