Cybersecurity researchers have uncovered a critical remote code execution (RCE) vulnerability in Langflow, an open-source platform widely used for visually composing AI-driven agents and workflows. The security flaw affects all Langflow versions prior to 1.3.0 and enables attackers to execute arbitrary commands on vulnerable servers without requiring authentication, potentially compromising sensitive data and systems. The researchers emphasized that this vulnerability demonstrates the critical importance of implementing proper authentication and sandboxing measures when working with dynamic code execution. The complete attack chain showing how attackers progress from targeting the vulnerable endpoint to achieving code execution on the server. Organizations leveraging Langflow in their AI development workflows face significant risks as attackers can exploit this flaw to gain unauthorized system access and execute commands with the privileges of the application server. The vulnerability specifically targets Langflow’s /api/v1/validate/code endpoint, which improperly invokes Python’s built-in exec() function on user-supplied code. When Langflow processes code through its validation endpoint, attackers can inject malicious payloads using two primary methods. The attack leverages Python’s function definition behavior in creative ways to achieve code execution. Examining the technical implementation reveals that Langflow’s code validation mechanism attempts to parse user-submitted code into an AST before evaluating specific components, including function definitions. Cyber Security News is a Dedicated News Platform For Cyber News, Cyber Attack News, Hacking News & Vulnerability Analysis. Zscaler researchers identified that the vulnerability stems from Python’s behavior during function definition processing, where decorators and default argument values are evaluated immediately. This characteristic allows malicious code embedded within these structures to execute during the Abstract Syntax Tree (AST) processing phase. The first approach embeds commands within function decorators, which execute immediately during code processing. Once access is gained, attackers can leverage the vulnerable endpoint to establish persistent access, exfiltrate data, or move laterally within affected networks. The exploit allows attackers to target publicly accessible Langflow instances or compromise internal deployments through various attack vectors. While the server’s response appears benign, the malicious code executes silently in the background, potentially creating backdoors or exfiltrating data. This implementation lacks proper authentication checks and sandboxing protections, creating a dangerous attack surface for malicious actors. Organizations using Langflow are strongly advised to upgrade immediately to version 1.3.0 or later, which requires authentication for the vulnerable endpoint. This process involves importing specified modules and executing function definitions to validate their structure, but critically fails to restrict the execution context. With years of experience under his belt in Cyber Security, he is covering Cyber Security News, technology and other news.
This Cyber News was published on cybersecuritynews.com. Publication date: Thu, 24 Apr 2025 12:05:08 +0000