CVE-2023-5764 in Ansible
Summary
by MITRE • 12/13/2023
A template injection flaw was found in Ansible where a user's controller internal templating operations may remove the unsafe designation from template data. This issue could allow an attacker to use a specially crafted file to introduce templating injection when supplying templating data.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/02/2025
The vulnerability identified as CVE-2023-5764 represents a critical template injection flaw within the Ansible automation platform that fundamentally compromises the security of controller internal templating operations. This vulnerability resides in the core templating engine where user-supplied data undergoes processing, creating an environment where potentially dangerous template content can bypass intended security measures. The flaw specifically manifests when the controller's internal templating system removes the unsafe designation from template data, effectively neutralizing protective mechanisms that should prevent malicious content from executing within the templating context.
The technical implementation of this vulnerability stems from improper handling of template data sanitization within Ansible's controller operations. When users provide templating data through various interfaces or configuration files, the system's internal processing logic fails to maintain the appropriate security context that would normally mark such data as potentially unsafe. This removal of the unsafe designation creates a pathway for attackers to inject malicious template code that would otherwise be rejected or properly escaped. The vulnerability operates at the intersection of input validation and output encoding, where the system's failure to maintain security context during templating operations creates an exploitable condition.
From an operational impact perspective, this vulnerability presents significant risks to organizations relying on Ansible for automation and configuration management. Attackers can leverage this flaw to execute arbitrary template code through specially crafted files, potentially leading to unauthorized access, data exfiltration, or system compromise. The attack surface extends to any scenario where Ansible processes user-supplied template data, including playbook execution, role parameter handling, or configuration file processing. Organizations utilizing Ansible's controller capabilities for managing critical infrastructure face elevated risk as attackers can manipulate the templating system to execute malicious payloads within the automation environment. This vulnerability directly violates the principle of least privilege and can enable attackers to escalate their privileges within the automation framework.
The security implications of CVE-2023-5764 align with CWE-94, which describes weaknesses in the generation of code from external inputs, and specifically relates to the improper handling of template injection vulnerabilities. This flaw also maps to ATT&CK technique T1059.001, which covers command and scripting interpreter execution, as the vulnerability could enable attackers to execute arbitrary commands through template injection. Organizations should consider implementing multiple layers of defense including input validation, template sanitization, and strict access controls around Ansible controller interfaces. The recommended mitigations include upgrading to patched versions of Ansible, implementing strict template validation policies, and monitoring for unauthorized template modifications. Additionally, organizations should review their Ansible configurations to ensure that template data sources are properly sanitized and that only trusted users have access to template creation and modification capabilities. The vulnerability underscores the critical importance of maintaining security context throughout all stages of template processing and highlights the need for comprehensive input validation in automation platforms.