CVE-2023-49920 in Airflow
Summary
by MITRE • 12/21/2023
Apache Airflow, version 2.7.0 through 2.7.3, has a vulnerability that allows an attacker to trigger a DAG in a GET request without CSRF validation. As a result, it was possible for a malicious website opened in the same browser - by the user who also had Airflow UI opened - to trigger the execution of DAGs without the user's consent. Users are advised to upgrade to version 2.8.0 or later which is not affected
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Analysis
by VulDB Data Team • 01/14/2024
Apache Airflow version 2.7.0 through 2.7.3 contains a critical security flaw that exposes the platform to unauthorized DAG execution through cross-site request forgery attacks. This vulnerability specifically affects the GET request handling mechanism within the Airflow user interface, where the system fails to validate CSRF tokens before executing Directed Acyclic Graphs. The flaw allows attackers to craft malicious web pages that can trigger DAG executions when users browse to these sites while having an active Airflow session open in their browser. This represents a classic CSRF vulnerability where the attacker exploits the user's authenticated session to perform unauthorized actions without their knowledge or consent. The vulnerability is particularly dangerous because it requires no authentication from the attacker, relying solely on the victim's existing session within the same browser context. This attack vector aligns with CWE-352, which categorizes Cross-Site Request Forgery vulnerabilities, and demonstrates how session management flaws can be exploited to compromise system integrity.
The technical implementation of this vulnerability stems from insufficient input validation in the Airflow web interface's DAG execution endpoints. When users navigate to the Airflow UI and maintain an active session, their browser stores authentication cookies that are automatically included with subsequent requests. Attackers can leverage this by creating malicious web pages containing hidden forms or javascript that submit GET requests to the vulnerable Airflow endpoints. The absence of CSRF token validation means that these requests are processed as legitimate user actions, bypassing the normal authorization checks. This flaw specifically impacts the Airflow web server's ability to distinguish between authorized and unauthorized requests, creating a scenario where user consent is effectively bypassed. The vulnerability is particularly insidious because it requires no special privileges or credentials from the attacker, making it accessible to anyone who can host a malicious website.
The operational impact of this vulnerability extends beyond simple unauthorized execution, as it creates a potential attack surface for more sophisticated compromise scenarios. An attacker could orchestrate a campaign to trigger critical DAGs that perform sensitive operations such as data exports, system modifications, or process initiations that could result in data loss, service disruption, or system compromise. The vulnerability also creates a risk for business continuity, as unauthorized DAG executions could interfere with scheduled operations or trigger unintended workflows. In enterprise environments where Airflow manages critical data processing pipelines, this vulnerability could lead to significant operational disruptions. The attack scenario represents a form of browser-based attack that aligns with ATT&CK technique T1566.001, which covers the use of malicious websites for initial access. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous for organizations that do not maintain up-to-date security practices.
Organizations using affected Apache Airflow versions should immediately implement the recommended upgrade to version 2.8.0 or later, which includes the necessary CSRF validation fixes. In addition to upgrading, administrators should review their network configurations to limit direct exposure of Airflow UI components to untrusted networks. The mitigation strategy should include implementing proper access controls and network segmentation to reduce the attack surface. Organizations should also consider implementing additional monitoring and alerting for unauthorized DAG executions, particularly for critical workflows. Security teams should conduct thorough assessments of their Airflow deployments to identify any additional configurations that might be vulnerable to similar CSRF attacks. The fix in version 2.8.0 addresses the core validation issue by implementing proper CSRF token verification for all DAG execution requests, ensuring that only authenticated and authorized requests can trigger workflow execution. This vulnerability serves as a reminder of the importance of maintaining current security practices and the critical need for regular security updates in enterprise software environments.