Description

Flight vulnerable to SQL Injection via unvalidated identifiers in SimplePdo::insert / update / delete

Summary

SimplePdo::insert(), SimplePdo::update(), and SimplePdo::delete() build SQL statements by concatenating the $table argument and the keys of the $data array directly into the query, with no identifier quoting and no validation. When an application forwards user-controlled data shapes to these helpers — a common and documented pattern, e.g. $db->insert('users', $request->data->getData()) — an attacker can inject arbitrary SQL by crafting malicious array keys.

Affected code

flight/database/SimplePdo.php:

// insert (≈ 320-373)
$sql = sprintf(
    "INSERT INTO %s (%s) VALUES (%s)",
    $table,                            // raw concat
    implode(', ', $columns),           // raw array_keys($data)
    implode(', ', $placeholders)
);
...
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No identifier-quoting helper exists; neither $table nor the data keys are validated against a safe-identifier pattern.

Proof of concept

A controller does:

$db->insert('users', $request->data->getData());

The attacker sends the JSON body:

{"name, is_admin) VALUES (?, 1);-- ": "attacker_injected"}

Generated SQL:

INSERT INTO users (name, is_admin) VALUES (?, 1);-- ) VALUES (?)

After the -- comment, the effective statement INSERT INTO users (name, is_admin) VALUES (?, 1) binds the single placeholder 'attacker_injected', yielding a row with is_admin = 1.

Reproduced live on an in-memory sqlite database (testproj/sqli_live2.php):

id=1  name=alice              is_admin=0
id=2  name=attacker_injected  is_admin=1   <-- injected insert

UPDATE injection via the $where parameter was also reproduced: $db->update('users', ['is_admin' => 1], "id = 1 OR 1=1") flips admin on every row.

Impact

Privilege escalation on any signup / register endpoint that forwards request data to insert() (attacker creates an administrative account in a single request).

Arbitrary column write through update() keys.

Data destruction and exfiltration through the $where parameter (DELETE FROM users WHERE 1=1, UNION-based exfil, etc.).

Patch (fixed in 3.18.1, commit b8dd23a)

A new requireSafeIdentifier() helper validates table names and column names against ^[A-Za-z_][A-Za-z0-9_]*$ before they are interpolated into the SQL string. The $where parameter remains raw SQL as documented — parameterized values passed alongside it continue to be bound safely.

Credit

Discovered by @Rootingg.

Mitigation

Aliases

References