CVE-2023-22506: Atlassian Bamboo Data Center RCE Flaw

CVE-2023-22506 Overview

CVE-2023-22506 is a high severity Injection and Remote Code Execution (RCE) vulnerability affecting Atlassian Bamboo Data Center and Bamboo Server. This vulnerability allows an authenticated attacker to modify the actions taken by a system call and execute arbitrary code on the affected system.

The vulnerability was introduced in version 8.0.0 of Bamboo Data Center and affects both Bamboo Data Center and Bamboo Server products. Successful exploitation results in high impact to confidentiality, integrity, and availability of the affected system, with no user interaction required beyond initial authentication.

Critical Impact

Authenticated attackers can achieve arbitrary code execution on Bamboo Data Center and Server instances, potentially leading to complete system compromise, data theft, and lateral movement within enterprise CI/CD infrastructure.

Affected Products

• Atlassian Bamboo Data Center (versions 8.0.0 and later, prior to fixed versions)
• Atlassian Bamboo Server (versions 8.0.0 and later, prior to fixed versions)

Discovery Timeline

• 2023-07-19 - CVE-2023-22506 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-22506

Vulnerability Analysis

This vulnerability falls under CWE-94 (Improper Control of Generation of Code, also known as Code Injection). The flaw allows an authenticated user to manipulate system call actions, effectively enabling the injection of malicious code that gets executed by the Bamboo server process.

Bamboo Data Center is a continuous integration and deployment (CI/CD) tool widely used in enterprise environments. The ability to execute arbitrary code within such a system is particularly dangerous as it provides attackers with access to build pipelines, source code repositories, deployment credentials, and potentially the entire software supply chain.

The vulnerability requires authentication, meaning an attacker must first obtain valid credentials or compromise an existing Bamboo user account before exploitation is possible. However, once authenticated, the attacker can leverage this vulnerability without any additional user interaction.

Root Cause

The root cause of CVE-2023-22506 is improper control of code generation (CWE-94). The vulnerability exists because the application fails to properly sanitize or validate user-controlled input that influences system call behavior. This allows authenticated users to inject malicious commands or code that the system then executes with the privileges of the Bamboo server process.

The injection point enables modification of system call actions, suggesting that user input is being incorporated into command execution contexts without adequate input validation or output encoding.

Attack Vector

The attack vector is network-based, requiring low complexity to exploit. An authenticated attacker can remotely target vulnerable Bamboo instances over the network. The attack flow typically involves:

1. Attacker authenticates to the Bamboo instance using valid credentials
2. Attacker crafts malicious input designed to inject code into system call operations
3. The vulnerable component processes the malicious input without proper sanitization
4. The injected code executes with the privileges of the Bamboo server process
5. Attacker achieves arbitrary code execution on the target system

Since Bamboo Data Center and Server are typically deployed as critical CI/CD infrastructure with access to source code, build artifacts, and deployment credentials, successful exploitation can have devastating consequences for an organization's software supply chain security.

Detection Methods for CVE-2023-22506

Indicators of Compromise

• Unusual process spawning from Bamboo server processes, particularly shell or command interpreters
• Unexpected network connections originating from the Bamboo server to external IP addresses
• Anomalous file system modifications in Bamboo installation directories or system paths
• Authentication logs showing unusual access patterns or privilege usage by Bamboo users

Detection Strategies

• Monitor Bamboo server process trees for unexpected child processes or command execution
• Implement application-level logging to capture and analyze API requests and system call invocations
• Deploy endpoint detection and response (EDR) solutions to identify code injection attempts and suspicious process behavior
• Review Bamboo audit logs for unusual user activities, particularly those involving build configurations or plugin modifications

Monitoring Recommendations

• Enable comprehensive logging on Bamboo Data Center and Server instances and forward logs to a SIEM solution
• Configure alerts for process execution anomalies on systems running Bamboo
• Implement network segmentation and monitor egress traffic from CI/CD infrastructure
• Regularly review user access and permissions within Bamboo to minimize attack surface

How to Mitigate CVE-2023-22506

Immediate Actions Required

• Upgrade Atlassian Bamboo Data Center and Server to the latest available version immediately
• If immediate upgrade is not possible, apply fixed versions 9.2.3 or 9.3.1 as interim remediation
• Review and audit all Bamboo user accounts to ensure no unauthorized access has occurred
• Implement network segmentation to limit access to Bamboo instances from untrusted networks

Patch Information

Atlassian has released patches addressing this vulnerability. The recommended action is to upgrade to the latest version of Bamboo Data Center and Server. If upgrading to the latest version is not immediately feasible, organizations should upgrade to one of the fixed versions: 9.2.3 or 9.3.1.

Detailed release notes are available from Atlassian's Bamboo Release Notes. The latest versions can be downloaded from Atlassian's Download Center.

For additional details on this vulnerability, refer to Atlassian Jira Issue BAM-22400.

Workarounds

• Restrict network access to Bamboo instances using firewall rules, allowing only trusted IP ranges
• Implement strict authentication controls and consider enabling multi-factor authentication for all Bamboo users
• Conduct regular audits of user permissions and remove unnecessary accounts or elevated privileges
• Monitor for exploitation attempts while planning and executing the upgrade process

# Example: Restrict Bamboo access using iptables (Linux)
# Allow access only from trusted internal network
iptables -A INPUT -p tcp --dport 8085 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8085 -j DROP

# Verify Bamboo version (check for vulnerable versions 8.0.0 to pre-9.2.3/9.3.1)
cat /opt/atlassian/bamboo/atlassian-bamboo/META-INF/maven/com.atlassian.bamboo/atlassian-bamboo-web-app/pom.properties | grep version