CVE-2022-2084: Sensitive Data Leakage through World Readable Logs in Cloud-init (Versions Prior to 22.3)

The latest vulnerability, known as CVE-2022-2084, has been identified in cloud-init, potentially allowing sensitive information to be exposed in world-readable logs when schema failures are reported. This article will provide an in-depth analysis of the vulnerability, a code snippet demonstrating the issue, and links to original references and exploit details - all in simple American language for your comprehension.

Background

Cloud-init is a widely-used tool for initializing cloud instances, virtual machines, and bare-metal servers. It sets up users, installs packages, and configures networking as well as performing various other tasks during instance initialization. The vulnerability exists in cloud-init versions prior to 22.3, and sensitive information in world-readable logs, such as hashed passwords, could be exposed.

Vulnerability Details

The vulnerability is triggered when schema failures are reported during the initialization process. In this case, the affected cloud-init versions might expose sensitive data in the system's logs, which are accessible by every user. A potential attacker with access to the machine could then compromise those logs and gain sensitive information, putting the system at risk of further attacks.

The vulnerability is present in cloud-init versions older than 22.3, which means that upgrading to the latest version will eliminate this issue.

Code Snippet

Below is a code snippet showing an example of a schema failure in cloud-init that could lead to exposure of sensitive data:

try:
    config = handle_schema_validation(config)
except schema.SchemaError as e:
    LOG.warning("Failed schema validation of cloud instance: %s", str(e))
    LOG.warning("Dumping cloud-init config in world-readable log: %s", config)
    raise

In this example, when the schema validation of the configuration fails, the error is logged along with the contents of the entire configuration file. This may inadvertently expose sensitive information in the logs.

Mitigation

To protect yourself from CVE-2022-2084 and the potential exposure of sensitive data, follow these steps:

For more information on CVE-2022-2084, you can refer to these original references and resources

1. CVE-2022-2084 vulnerability details: link
2. Cloud-init GitHub repository: link
3. Cloud-init Release Notes (including version 22.3): link
4. Advisory for CVE-2022-2084: link

Conclusion

The CVE-2022-2084 vulnerability in earlier versions of cloud-init may lead to sensitive data exposure in world-readable logs. Be sure to either upgrade your cloud-init to version 22.3 or above, or implement necessary precautions to prevent the leakage of sensitive data. Always keep your software up-to-date and follow recommended security practices to stay protected against potential threats.

Timeline

Published on: 04/19/2023 22:15:00 UTC
Last modified on: 05/01/2023 17:39:00 UTC