CVE-2024-21673: Confluence Data Center RCE Vulnerability

CVE-2024-21673 Overview

CVE-2024-21673 is a Remote Code Execution (RCE) vulnerability affecting Atlassian Confluence Data Center and Server. This vulnerability was introduced in version 7.13.0 and allows an authenticated attacker to execute arbitrary code on vulnerable Confluence instances. The vulnerability enables attackers to expose assets in the environment susceptible to exploitation, resulting in high impact to confidentiality, integrity, and availability of affected systems.

The vulnerability is classified as Code Injection (CWE-94), indicating that an attacker can inject malicious code that is subsequently executed by the application. This type of vulnerability is particularly dangerous in enterprise collaboration platforms like Confluence, where successful exploitation could lead to complete system compromise and lateral movement within organizational networks.

Critical Impact

Authenticated remote code execution allowing attackers to fully compromise Confluence instances with high impact to confidentiality, integrity, and availability. Organizations using vulnerable versions should prioritize immediate patching.

Affected Products

• Atlassian Confluence Data Center versions 7.13.0 through 7.19.17
• Atlassian Confluence Data Center versions 8.0.0 through 8.5.4
• Atlassian Confluence Data Center versions 8.6.0 through 8.7.1
• Atlassian Confluence Server versions 7.13.0 through 7.19.17
• Atlassian Confluence Server versions 8.0.0 through 8.5.4
• Atlassian Confluence Server versions 8.6.0 through 8.7.1

Discovery Timeline

• January 16, 2024 - CVE-2024-21673 published to NVD
• June 03, 2025 - Last updated in NVD database

Technical Details for CVE-2024-21673

Vulnerability Analysis

This Remote Code Execution vulnerability stems from improper code injection controls (CWE-94) within Atlassian Confluence Data Center and Server. The vulnerability requires an authenticated user context, meaning attackers must first obtain valid credentials to exploit this flaw. However, once authenticated, the attacker can leverage the vulnerability to execute arbitrary code on the underlying server.

The attack can be conducted over the network without requiring user interaction, making it particularly concerning for internet-facing Confluence deployments. Successful exploitation grants attackers the ability to execute commands with the privileges of the Confluence application service account, potentially leading to complete system compromise.

The changed scope indicator in the vulnerability assessment suggests that exploitation can impact resources beyond the vulnerable component itself, potentially affecting other systems and services within the same security domain.

Root Cause

The root cause of CVE-2024-21673 is a Code Injection vulnerability (CWE-94) in the Confluence application. Code injection flaws occur when an application fails to properly validate, sanitize, or neutralize code syntax elements in user-controllable input before using it in dynamically generated code statements. In this case, the vulnerability allows authenticated users to inject and execute arbitrary code through improperly handled input within Confluence's processing logic.

Attack Vector

The attack vector for CVE-2024-21673 is network-based, requiring the attacker to have authenticated access to a vulnerable Confluence instance. The attack flow involves:

1. Authentication: Attacker obtains valid Confluence credentials through credential theft, phishing, or compromised accounts
2. Exploitation: Using authenticated access, the attacker crafts malicious requests containing injected code
3. Execution: The vulnerable Confluence component processes the malicious input, executing the injected code
4. Impact: The attacker gains code execution capabilities on the server, enabling data exfiltration, system manipulation, or further lateral movement

The vulnerability does not require any user interaction beyond the initial authentication, and the attack complexity is relatively low once valid credentials are obtained. Organizations should consider that compromised low-privilege accounts can potentially be leveraged to achieve full system compromise through this vulnerability.

Detection Methods for CVE-2024-21673

Indicators of Compromise

• Unusual process spawning from Confluence Java processes, particularly command shells or scripting interpreters
• Unexpected outbound network connections from Confluence servers to external IP addresses
• Anomalous file system modifications in Confluence installation directories or temporary folders
• Authentication anomalies showing unusual access patterns from authenticated users
• Web access logs containing suspicious POST requests with encoded or obfuscated payloads

Detection Strategies

• Monitor Confluence application logs for error messages indicating code execution attempts or injection patterns
• Implement network traffic analysis to detect command-and-control communications from Confluence servers
• Deploy endpoint detection and response (EDR) solutions to identify suspicious process behavior on Confluence hosts
• Configure web application firewalls (WAF) to detect and block common code injection patterns
• Enable detailed audit logging in Confluence to track user actions that could indicate exploitation attempts

Monitoring Recommendations

• Establish baseline behavior patterns for Confluence server processes and network connections
• Configure alerting for any shell process execution originating from Confluence Java processes
• Monitor for unusual file creation or modification events in web-accessible directories
• Track authentication events and flag anomalous access patterns such as off-hours logins or geographic impossibilities
• Review Confluence access logs regularly for requests to administrative functions from unexpected user accounts

How to Mitigate CVE-2024-21673

Immediate Actions Required

• Upgrade Confluence Data Center and Server to the latest available version immediately
• If immediate upgrade is not possible, apply the specified fixed versions: 7.19.18, 8.5.5, or 8.7.2
• Restrict network access to Confluence instances, limiting exposure to trusted networks only
• Review and audit all user accounts for unnecessary privileges and remove dormant accounts
• Implement additional authentication controls such as multi-factor authentication (MFA) for all Confluence users

Patch Information

Atlassian has released security patches addressing CVE-2024-21673. Organizations should upgrade to the following fixed versions based on their current deployment:

• Confluence Data Center and Server 7.19.x: Upgrade to version 7.19.18 or any higher 7.19.x release
• Confluence Data Center and Server 8.5.x: Upgrade to version 8.5.5 or any higher 8.5.x release
• Confluence Data Center and Server 8.7.x: Upgrade to version 8.7.2 or any higher release

Patches are available through the Atlassian Download Center. Detailed release notes are available at the Confluence Release Notes page. Additional technical details can be found in the Atlassian Security Bulletin January 2024 and the CONFSERVER-94065 JIRA issue.

Workarounds

• Restrict Confluence access to internal networks only by placing it behind a VPN or firewall with strict access controls
• Implement IP allowlisting to limit which hosts can connect to Confluence
• Disable or restrict access to administrative and potentially vulnerable features until patching is complete
• Monitor authenticated sessions closely and implement session timeout policies
• Consider temporarily disabling public-facing Confluence instances if patching cannot be performed immediately

# Example: Restrict Confluence access via iptables firewall rules
# Allow only trusted internal network ranges to access Confluence
iptables -A INPUT -p tcp --dport 8090 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8090 -s 192.168.0.0/16 -j ACCEPT
iptables -A INPUT -p tcp --dport 8090 -j DROP

# Enable detailed access logging in Confluence
# Add to confluence/WEB-INF/classes/log4j.properties
# log4j.logger.com.atlassian.confluence.security=DEBUG