CVE-2021-37694 in java-spring-cloud-stream-template
Summary
by MITRE • 08/12/2021
@asyncapi/java-spring-cloud-stream-template generates a Spring Cloud Stream (SCSt) microservice. In versions prior to 0.7.0 arbitrary code injection was possible when an attacker controls the AsyncAPI document. An example is provided in GHSA-xj6r-2jpm-qvxp. There are no mitigations available and all users are advised to update.
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Analysis
by VulDB Data Team • 08/16/2021
The vulnerability CVE-2021-37694 affects the asyncapi/java-spring-cloud-stream-template component which is used to generate Spring Cloud Stream microservices from AsyncAPI documents. This template engine processes AsyncAPI specifications to automatically generate code for Spring Cloud Stream applications, creating a powerful automation tool for developers working with event-driven architectures. The flaw exists in versions prior to 0.7.0 where the template processing logic fails to properly sanitize user-provided AsyncAPI documents, creating a path for arbitrary code injection attacks.
The technical flaw stems from insufficient input validation and sanitization within the template rendering process. When an attacker can control the AsyncAPI document that gets processed by this template, they can inject malicious code that gets executed during the code generation phase. This represents a critical security weakness where the template engine treats user-supplied content as executable code rather than safe data. The vulnerability allows for arbitrary code execution during the generation of Spring Cloud Stream microservices, potentially enabling attackers to inject malicious code into the generated applications. This type of vulnerability maps to CWE-94 - Improper Control of Generation of Code ('Code Injection') and aligns with ATT&CK technique T1059.006 - Command and Scripting Interpreter: Python, which covers code injection scenarios in automated code generation systems.
The operational impact of this vulnerability is severe as it affects the entire code generation pipeline for Spring Cloud Stream microservices. An attacker who can influence the AsyncAPI document used in the generation process can inject malicious code that will be compiled and executed within the target system. This could lead to complete system compromise, data exfiltration, or the deployment of backdoors within the generated microservices. The vulnerability is particularly dangerous because it operates at the code generation level, meaning that any service using this template to process untrusted AsyncAPI documents becomes vulnerable. This attack vector could be exploited in continuous integration pipelines, automated deployment systems, or any environment where AsyncAPI documents are processed through this template engine.
Organizations using the asyncapi/java-spring-cloud-stream-template should immediately update to version 0.7.0 or later to address this vulnerability. Since no mitigations are available for the affected versions, the recommended approach is to perform an immediate upgrade of the template component. Additionally, organizations should review their code generation processes to ensure that any AsyncAPI documents being processed come from trusted sources and implement proper input validation mechanisms. The vulnerability demonstrates the critical importance of securing code generation tools and highlights the need for proper sanitization of inputs in automated development environments. This issue represents a significant risk to DevOps pipelines and automated deployment systems where code generation tools are used to create production applications from specification documents.