CVE-2022-38170 in Airflow
Summary
by MITRE • 09/02/2022
In Apache Airflow prior to 2.3.4, an insecure umask was configured for numerous Airflow components when running with the `--daemon` flag which could result in a race condition giving world-writable files in the Airflow home directory and allowing local users to expose arbitrary file contents via the webserver.
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Analysis
by VulDB Data Team • 10/11/2022
The vulnerability identified as CVE-2022-38170 affects Apache Airflow versions prior to 2.3.4 and represents a critical security flaw related to improper file permission handling during daemonized operations. This issue stems from an insecure umask configuration that impacts multiple Airflow components when executed with the --daemon flag, creating a significant attack surface for local privilege escalation and information disclosure. The flaw specifically manifests when Airflow processes are started in daemon mode, which is commonly used in production environments for continuous service operation. The insecure umask configuration allows for world-writable files to be created in the Airflow home directory, effectively providing unauthorized local users with the ability to modify or access sensitive files that should remain restricted. This race condition vulnerability occurs during the initialization phase of daemon processes, where temporary files and directories are created with overly permissive permissions that persist beyond the initial setup. The impact extends beyond simple file access as it enables arbitrary file content exposure through the webserver component, which is a core element of Airflow's user interface and administrative capabilities. This vulnerability directly violates fundamental security principles of least privilege and proper access control enforcement, creating a persistent risk for systems running affected versions of Apache Airflow.
The technical implementation of this vulnerability involves the improper configuration of umask values during the daemon startup process, which controls the default permissions for newly created files and directories. When Airflow components are launched with the --daemon flag, they execute under a process context that inherits an insecure umask setting of 0000 or similar permissive values, rather than the standard restrictive umask of 077 that should be applied to prevent world-writable permissions. This configuration flaw creates a race condition where multiple processes may simultaneously create files in the Airflow home directory with 777 permissions, allowing any local user to write to these files and potentially overwrite critical system components or inject malicious content. The vulnerability is particularly dangerous because it affects the webserver component, which serves as the primary interface for Airflow administrators and users, enabling attackers to access sensitive configuration files, log data, and potentially execute arbitrary code through file manipulation. The race condition aspect of this vulnerability means that timing attacks or concurrent process execution can be leveraged to maximize the impact, as multiple processes may create files with the same insecure permissions, increasing the window of opportunity for exploitation.
The operational impact of CVE-2022-38170 extends far beyond simple file permission issues and represents a serious threat to the integrity and confidentiality of Apache Airflow installations. Local users with minimal privileges can exploit this vulnerability to gain unauthorized access to sensitive data, including but not limited to database connection strings, API keys, and other credential information stored within the Airflow home directory. The webserver exposure aspect allows attackers to potentially read arbitrary file contents, which could include sensitive workflow definitions, task configurations, and execution logs that may contain personal identifiable information or proprietary business data. Organizations running affected versions of Airflow face significant risk of data breaches, unauthorized workflow modifications, and potential system compromise if attackers can leverage this vulnerability to escalate privileges or inject malicious code into the workflow execution environment. The vulnerability also impacts the overall security posture of systems that rely on Airflow for workflow automation, as it undermines the trust model of the platform and creates persistent attack vectors that remain active as long as the vulnerable software remains in operation. This issue particularly affects organizations with shared or multi-tenant environments where multiple users may have access to the same system resources, amplifying the potential impact of unauthorized file access and modification.
The mitigation strategy for CVE-2022-38170 centers on upgrading to Apache Airflow version 2.3.4 or later, which includes the necessary fixes to properly configure umask values for daemonized processes and eliminate the race condition that enables world-writable file creation. Organizations should prioritize immediate deployment of the patched version across all affected systems and conduct thorough security assessments to identify any potential exploitation that may have occurred before the patch was applied. System administrators should also implement additional monitoring controls to detect unauthorized file modifications in the Airflow home directory and establish proper file permission auditing procedures to identify any lingering insecure configurations. The fix implemented in version 2.3.4 specifically addresses the umask configuration by ensuring that daemon processes initialize with restrictive permissions that prevent world-writable files from being created, aligning with security best practices established in industry standards such as the CWE-732 principle of improper restriction of operations within a security domain. Organizations should also consider implementing additional security controls including mandatory access controls, file integrity monitoring, and regular security scanning to prevent similar vulnerabilities from occurring in other components of their workflow automation infrastructure. The ATT&CK framework categorizes this vulnerability under privilege escalation and credential access techniques, specifically targeting the T1078 legitimate credentials and T1548.001 valid accounts sub-techniques, making it a significant concern for organizations implementing comprehensive security monitoring and incident response procedures.