CVE-2021-21371

Tenable for Jira Cloud is an open source project designed to pull Tenable.io vulnerability data, then generate Jira Tasks and sub-tasks based on the vulnerabilities current state. It published in pypi as tenable-jira-cloud. In tenable-jira-cloud before version 1.1.21, it is possible to run arbitrary commands through the yaml.load() method. This could allow an attacker with local access to the host to run arbitrary code by running the application with a specially crafted YAML configuration file. This is fixed in version 1.1.21 by using yaml.safe_load() instead of yaml.load().

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://github.com/tenable/integration-jira-cloud/commit/f8c2095fd529e664e7fa25403a0a4a85bb3907d0
• https://github.com/tenable/integration-jira-cloud/security/advisories/GHSA-8278-88vv-x98r
• https://pypi.org/project/tenable-jira-cloud/
• https://pyyaml.docsforge.com/master/documentation/#loading-yaml
• https://github.com/tenable/integration-jira-cloud/commit/f8c2095fd529e664e7fa25403a0a4a85bb3907d0
• https://github.com/tenable/integration-jira-cloud/security/advisories/GHSA-8278-88vv-x98r
• https://pypi.org/project/tenable-jira-cloud/
• https://pyyaml.docsforge.com/master/documentation/#loading-yaml