CVE-2021-3532 in Ansible Tower
Summary
by MITRE • 06/09/2021
A flaw was found in Ansible where the secret information present in async_files are getting disclosed when the user changes the jobdir to a world readable directory. Any secret information in an async status file will be readable by a malicious user on that system. This flaw affects Ansible Tower 3.7 and Ansible Automation Platform 1.2.
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Analysis
by VulDB Data Team • 08/22/2022
This vulnerability resides in Ansible's handling of asynchronous job execution files and represents a critical information disclosure flaw that directly impacts the security posture of automation platforms. The vulnerability stems from Ansible's improper management of temporary files containing sensitive data during asynchronous operations, where secret information is stored in files that can be accessed by unauthorized users when the job directory is configured to be world-readable. The flaw specifically affects Ansible Tower 3.7 and Ansible Automation Platform 1.2, indicating this is a platform-level security issue rather than a core Ansible engine vulnerability. This type of information disclosure vulnerability aligns with CWE-200, which addresses the exposure of sensitive information to an unauthorized actor, and represents a direct violation of the principle of least privilege in system security design.
The technical implementation of this vulnerability occurs during Ansible's asynchronous job processing where temporary files containing secrets such as passwords, API keys, or other sensitive credentials are written to disk without proper access controls. When administrators configure the job directory to be world-readable for operational convenience, these temporary files become accessible to any user on the system. The async_files contain metadata about job execution status including encrypted or plain-text secrets that are not properly secured, allowing malicious local users to extract sensitive information from these files. This issue demonstrates poor privilege separation and inadequate file permission management within the automation platform's temporary file handling mechanism, creating a direct attack surface that violates fundamental security principles.
The operational impact of this vulnerability is severe as it enables local privilege escalation attacks and data exfiltration scenarios that can compromise the entire automation infrastructure. A malicious user with local access to the system can simply navigate to the configured job directory and read the async status files to extract sensitive credentials and authentication tokens that are used for various automation tasks. This vulnerability undermines the security model of Ansible Tower and Automation Platform, as it allows attackers to gain access to secrets that should remain protected even within a controlled environment. The impact extends beyond simple credential theft to potentially enable further attacks such as privilege escalation, lateral movement within the automation infrastructure, and unauthorized access to connected systems that rely on these automation credentials. This flaw directly maps to ATT&CK technique T1552.001, which covers "Credentials in Files" and represents a common vector for credential harvesting in compromised systems.
Mitigation strategies for this vulnerability should focus on implementing proper file access controls and secure temporary file management practices. Organizations should immediately ensure that job directories are configured with restrictive permissions, typically limiting access to the Ansible user and system administrators only. The recommended approach involves setting appropriate umask values and ensuring that temporary files are created with secure permissions that prevent unauthorized access. Additionally, administrators should consider implementing monitoring and alerting for unauthorized access attempts to sensitive directories and temporary files. The most effective long-term solution involves upgrading to patched versions of Ansible Tower and Automation Platform where the platform properly implements secure temporary file handling with appropriate access controls and encryption of sensitive data within async files. System administrators should also conduct comprehensive audits of all automation platform configurations to ensure that world-readable directories are not being used for job execution and that proper security policies are enforced throughout the automation infrastructure.