CISA Adds Langflow flaw to KEV Catalog

The Cybersecurity and Infrastructure Security Agency (CISA) has officially added CVE-2025-3248, a critical vulnerability in Langflow, to its Known Exploited Vulnerabilities (KEV) Catalog, citing active exploitation in the wild. Langflow is an open-source AI workflow builder used for visualizing and managing AI-driven agents, making this vulnerability particularly concerning for organizations relying on AI automation.

1. Overview of CVE-2025-3248

Description

• Vulnerability Type: Missing Authentication for Critical Function (CWE-306)
• Affected Component: /api/v1/validate/code endpoint
• Impact: Remote Code Execution (RCE)
• CVSS Score: 9.8 (Critical)

How It Works

• The vulnerability exists due to improper authentication in Langflow’s code validation endpoint.
• Attackers can send crafted HTTP requests to execute arbitrary Python code on vulnerable servers.
• The flaw arises from unsanitized use of Python’s exec() function, allowing unauthenticated remote attackers to run commands on the system.

2. Affected Versions

• Langflow versions prior to 1.3.0 are vulnerable.
• The issue was patched in Langflow 1.3.0, released on March 31, 2025.

3. Exploitation Details

Active Exploitation

• Security researchers at Horizon3.ai discovered and reported the flaw in February 2025.
• A proof-of-concept (PoC) exploit was publicly released on April 9, 2025, increasing the risk of widespread attacks.
• Censys data shows 466 internet-exposed Langflow instances, primarily in the U.S., Germany, Singapore, India, and China.

Potential Attack Scenarios

• Remote attackers can inject malicious Python code, such as reverse shells, to gain full control over Langflow servers.
• Exploited servers may be used for data exfiltration, system disruption, or further malware deployment.

4. Mitigation Strategies

A. Apply Security Updates

• Organizations using Langflow should immediately upgrade to version 1.3.0 or later.

B. Restrict Network Access

• Limit exposure of Langflow’s API endpoints to trusted IP addresses.
• Implement firewall rules to block unauthorized access.

C. Monitor for Exploitation

• Deploy Intrusion Detection Systems (IDS) to flag suspicious API requests.
• Audit logs for unauthorized execution attempts.

5. Compliance Requirements

Federal Agencies

Under Binding Operational Directive (BOD) 22-01, Federal Civilian Executive Branch (FCEB) agencies must apply patches by May 26, 2025.

6. Conclusion

The inclusion of CVE-2025-3248 in CISA’s KEV Catalog highlights the critical nature of this vulnerability. Organizations using Langflow must prioritize patching, restrict access, and monitor for exploitation to mitigate risks.