SQL Injection in Netmaker SQLite Database Backend

Summary

The sqliteDeleteRecord function in Netmaker's database layer constructs SQL DELETE statements using direct string concatenation of user-supplied input. This allows an authenticated attacker to perform boolean-based SQL injection.

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Details

The endpoint:

DELETE /api/dns/{network}/{domain}

passes user-controlled path parameters through the following flow:

logic.DeleteDNS → database.DeleteRecord → sqliteDeleteRecord

Depending on the configured database backend, the request eventually reaches the SQLite database implementation.

Vulnerable Code

The SQL query is constructed using direct string concatenation without parameterization.

// database/sqlite.go
deleteSQL := "DELETE FROM " + tableName + " WHERE key = \"" + key + "\""

The key value originates from user input ({domain} path parameter) and is embedded directly into the SQL query.

Exploitation

An authenticated attacker can inject SQL operators into the {domain} path parameter to manipulate the query logic.

Because this injection is boolean-based, attackers extract data indirectly by observing the outcome of the operation:

If the injected condition evaluates true, the DNS record is deleted.

If the condition evaluates false, the DNS record remains.

By repeating this process, an attacker can infer information such as:

Database table names

Column names

Column values

Value lengths

Impact

An authenticated attacker can exploit this vulnerability to extract data from arbitrary database tables when using the SQLite backend.

Unaffected backend:

PostgreSQL (uses parameterised queries with $1, $2 placeholders)

Patches

This vulnerability is fixed in version (fill in).

The patch replaces string concatenation with parameterised SQL queries for all user-supplied values in database operations.


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Credit

Artem Danilov
(Positive Technologies)

Daniil Satyaev (Independent)