CVE-2020-1734 in Ansible
Summary
by MITRE
A flaw was found in the pipe lookup plugin of ansible. Arbitrary commands can be run, when the pipe lookup plugin uses subprocess.Popen() with shell=True, by overwriting ansible facts and the variable is not escaped by quote plugin. An attacker could take advantage and run arbitrary commands by overwriting the ansible facts.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability identified as CVE-2020-1734 resides within the pipe lookup plugin of the Ansible automation framework, representing a critical security flaw that enables arbitrary command execution under specific conditions. This vulnerability stems from improper handling of user-controlled data within the plugin's implementation, creating a pathway for malicious actors to execute unauthorized commands on systems where Ansible is deployed. The flaw specifically manifests when the pipe lookup plugin employs subprocess.Popen() with shell=True parameter, which inherently creates a risk vector for command injection attacks.
The technical exploitation of this vulnerability requires an attacker to manipulate ansible facts through specific mechanisms that allow the injection of malicious payloads into the command execution pipeline. When ansible facts are overwritten with crafted input and subsequently processed by the pipe lookup plugin without proper sanitization or escaping, the shell=True parameter in subprocess.Popen() becomes a critical attack surface. The vulnerability demonstrates a failure in input validation and sanitization processes, where the quote plugin fails to properly escape variables before they are incorporated into shell commands, creating an environment where attacker-controlled data can be interpreted as executable commands rather than mere data.
The operational impact of CVE-2020-1734 extends beyond simple command execution, as it represents a privilege escalation vector that can compromise entire automation infrastructure. Since Ansible is commonly used for system administration and deployment tasks, an attacker who successfully exploits this vulnerability gains the ability to execute arbitrary commands with the privileges of the Ansible user, potentially leading to full system compromise or lateral movement within network environments. This vulnerability particularly affects environments where Ansible is used for configuration management, deployment automation, or orchestration tasks, as it undermines the security assumptions of the automation framework.
Security professionals should note that this vulnerability aligns with CWE-78, which describes improper neutralization of special elements used in OS commands, and represents a classic command injection flaw. The ATT&CK framework categorizes this as a command and scripting interpreter execution technique, specifically targeting the use of shell commands within automation frameworks. Organizations should prioritize patching this vulnerability by updating to Ansible versions that address the improper handling of user input in the pipe lookup plugin, while also implementing monitoring for unusual command execution patterns that might indicate exploitation attempts. The vulnerability underscores the importance of proper input sanitization and the principle of least privilege in automation tooling, as it demonstrates how seemingly benign plugin functionality can become a critical attack vector when proper security controls are absent.