CVE-2021-43840 : What You Need to Know
Learn about CVE-2021-43840 affecting message_bus versions prior to 3.3.7, enabling path traversal and disclosure of secret information. Find mitigation steps and upgrade details here.
message_bus is a messaging bus for Ruby processes and web clients. In versions prior to 3.3.7, users are vulnerable to a path traversal bug, potentially leading to the disclosure of secret information on a machine. This CVE has a CVSS score of 4.4.
Understanding CVE-2021-43840
What is CVE-2021-43840?
message_bus, when deployed with diagnostics features enabled in versions before 3.3.7, is susceptible to a path traversal vulnerability. Attackers could exploit this to access sensitive data.
The Impact of CVE-2021-43840
The vulnerability could allow an unauthorized user to disclose confidential information on the host machine. The severity is higher without a web application proxy.
Technical Details of CVE-2021-43840
Vulnerability Description
The vulnerability in message_bus versions < 3.3.7 allows path traversal, potentially exposing secret information on the system if exploited.
Affected Systems and Versions
- Affected Product: message_bus
- Vendor: discourse
- Vulnerable Version: < 3.3.7
Exploitation Mechanism
- Attack Complexity: High
- Attack Vector: Network
- Confidentiality Impact: High
- Privileges Required: High
Mitigation and Prevention
Immediate Steps to Take
- Upgrade to version 3.3.7 or later to patch the vulnerability.
- Disable MessageBus::Diagnostics if unable to upgrade immediately.
Long-Term Security Practices
- Regularly update and maintain software to the latest versions.
- Implement proper access controls and network security measures.
Patching and Updates
Ensure all systems running message_bus update to version 3.3.7 or higher to mitigate the path traversal vulnerability.