Full Report
Learn about CVE-2025-3248 affecting Langflow. Patch now to prevent remote code execution.
Analysis Summary
# Vulnerability: Remote Code Execution in Langflow due to Missing Authentication
## CVE Details
- CVE ID: CVE-2025-3248
- CVSS Score: Critical (Score not explicitly provided, but context implies high severity due to RCE and KEV listing)
- CWE: Missing Authentication for Critical Function (Inferred from context, related to unauthenticated access to code execution)
## Affected Systems
- Products: Langflow
- Versions: Before 1.3.0
- Configurations: Any public-facing instance running a vulnerable version.
## Vulnerability Description
CVE-2025-3248 is a critical missing authentication vulnerability that allows remote, unauthenticated attackers to achieve Remote Code Execution (RCE). The flaw resides in the `"/api/v1/validate/code"` endpoint, which insecurely processes user-supplied code. Langflow parses user input using `ast.parse()` and then executes specific components using Python's `compile()` and `exec()` functions. Crucially, Python evaluates argument default values and decorators immediately upon compilation of the Abstract Syntax Tree (AST). By embedding malicious payloads within these default arguments or decorators in a crafted HTTP request to the endpoint, an attacker can force the server to compile and execute arbitrary code within the server context without authentication.
## Exploitation
- Status: Exploited in the wild (CISA KEV catalog inclusion)
- Complexity: Low (Implied by the ability for unauthenticated attackers to send crafted HTTP requests)
- Attack Vector: Network
## Impact
- Confidentiality: High (Potential for data exfiltration)
- Integrity: High (Potential for unauthorized code execution and system modification)
- Availability: High (Potential for system disruption)
## Remediation
### Patches
- Upgrade Langflow to version **1.3.0** or later.
### Workarounds
1. Restrict network access to the vulnerable endpoint using a firewall.
2. Block public access to the `"/api/v1/validate/code"` endpoint.
## Detection
- **Indicators of Compromise (IoC):** Suspicious POST requests targeting the `/api/v1/validate/code` endpoint. Observed exploitation leveraged remote commands such as deploying reverse shells.
- **Detection Methods and Tools:** Monitor network traffic/logs for POST requests to the specified endpoint. Custom detection rules (e.g., Nuclei templates provided by Insikt Group) can be used to test for vulnerabilities.
## References
- [Vendor advisories] (Implied, as an upgrade path is provided)
- [Relevant links - defanged]
- https://www.recordedfuture.com/vulnerability-database/CVE-2025-3248
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- https://www.shodan.io/search?query=html%3A%22Langflow%22
- https://viz.greynoise.io/query/CVE-2025-3248%20tags:%22Langflow%20Code%20Injection%20CVE-2025-3248%20RCE%20Attempt%22