CVE-2020-13944 in Airflow
Summary
by MITRE
In Apache Airflow < 1.10.12, the "origin" parameter passed to some of the endpoints like '/trigger' was vulnerable to XSS exploit.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/18/2020
Apache Airflow versions prior to 1.10.12 contained a cross-site scripting vulnerability in the trigger endpoint where the origin parameter was not properly sanitized before being rendered in the web interface. This flaw allowed attackers to inject malicious scripts that would execute in the context of other users' browsers when they visited affected pages. The vulnerability specifically impacted the /trigger endpoint which is used to initiate workflow executions and was particularly concerning given that Airflow is commonly used in enterprise environments where users may have elevated privileges. The issue stemmed from insufficient input validation and output encoding practices within the web application framework. According to CWE-79, this represents a classic cross-site scripting vulnerability where user-controllable data is directly embedded into web pages without proper sanitization. The attack vector was straightforward as it required only that a victim visit a malicious page containing the crafted payload or that an attacker could manipulate the trigger endpoint parameters through other means. This vulnerability could potentially be exploited to steal session cookies, perform unauthorized actions on behalf of users, or redirect users to malicious sites. The impact was significant in environments where Airflow was used for critical data processing workflows, as it could enable attackers to compromise the integrity of the entire data pipeline. Organizations using Airflow in production environments were particularly at risk since the tool often handles sensitive data and workflow automation tasks. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as the XSS could enable further exploitation. The remediation required implementing proper input validation and output encoding mechanisms to ensure that any user-supplied data passed to web endpoints was properly escaped before rendering. This involved updating the web application code to sanitize the origin parameter and similar inputs before they were processed by the rendering engine. Security teams should have implemented content security policies to further mitigate the risk of script execution. The fix required changes to the Airflow codebase to ensure that all user-controllable parameters were properly escaped when rendered in HTML contexts, addressing the root cause of the vulnerability. Organizations needed to upgrade to version 1.10.12 or later to receive the patched implementation. The vulnerability highlighted the importance of input validation in web applications and the potential for seemingly benign parameters to become attack vectors when not properly secured. This case study demonstrates how even simple parameter handling can create significant security risks in workflow automation platforms that are increasingly becoming targets for cyber attacks due to their central role in enterprise data processing.