CVE-2017-7466 in Ansible
Summary
by MITRE
Ansible before version 2.3 has an input validation vulnerability in the handling of data sent from client systems. An attacker with control over a client system being managed by Ansible, and the ability to send facts back to the Ansible server, could use this flaw to execute arbitrary code on the Ansible server using the Ansible server privileges.
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Analysis
by VulDB Data Team • 08/24/2024
The vulnerability identified as CVE-2017-7466 represents a critical input validation flaw within Ansible versions prior to 2.3, specifically affecting the way the automation platform processes data received from managed client systems. This issue stems from inadequate sanitization of facts submitted by client nodes to the central Ansible server, creating a potential attack vector that could be exploited by malicious actors who have compromised or gained control over client systems within the Ansible managed environment. The vulnerability operates at the intersection of configuration management and privilege escalation, where the trust relationship between client and server is improperly validated, allowing for arbitrary code execution with the privileges of the Ansible server process.
The technical implementation of this flaw involves the improper handling of structured data within Ansible's fact collection mechanism, where the server deserializes and processes client-provided information without sufficient validation or sanitization measures. When an attacker controls a client system that is managed by Ansible, they can craft malicious fact data that, when processed by the Ansible server, triggers unintended code execution. This represents a classic privilege escalation vulnerability where the attacker leverages their control over a client node to compromise the central management server, potentially gaining access to sensitive infrastructure and data across the entire Ansible-managed environment. The vulnerability is categorized under CWE-20 as "Improper Input Validation" and aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically focusing on the execution of arbitrary code through malformed input processing.
The operational impact of CVE-2017-7466 extends far beyond individual system compromise, as Ansible servers typically serve as central command and control points for infrastructure automation, making them prime targets for attackers seeking persistent access to enterprise environments. An attacker who successfully exploits this vulnerability can potentially execute commands with the same privileges as the Ansible server process, which often includes administrative access to multiple systems within the managed infrastructure. This could result in unauthorized access to sensitive data, deployment of malicious software across the network, modification of configuration files, or establishment of backdoors for continued access. The vulnerability is particularly concerning because it requires minimal prerequisites for exploitation, merely control over a single client system within the Ansible environment, making it a low-hanging fruit for attackers targeting organizations with Ansible-based infrastructure management.
Mitigation strategies for CVE-2017-7466 focus on both immediate remediation and long-term architectural improvements to reduce the attack surface and enhance security posture. The primary and most effective mitigation is upgrading to Ansible version 2.3 or later, where the input validation issues have been addressed through improved serialization and deserialization processes for fact data. Organizations should also implement network segmentation to limit communication between client systems and the Ansible server, ensuring that compromised client nodes cannot easily reach the central management server. Additional security controls include implementing strict access controls for Ansible server components, monitoring for unusual fact data patterns, and conducting regular security assessments of the Ansible infrastructure. The vulnerability demonstrates the importance of validating all input data, particularly in distributed automation systems where trust relationships between components can be exploited to escalate privileges and compromise entire infrastructure domains.