TypeORM's SelectQueryBuilder.distinctOn accepts an array of strings and stores it on the expression map without validation. For PostgreSQL-family drivers, createSelectDistinctExpression in src/query-builder/SelectQueryBuilder.ts joins that array and interpolates the result into the generated statement as SELECT DISTINCT ON (values), with no escaping, quoting, identifier validation or allowlist, and without routing the values through replacePropertyNames or the driver's escape helper. Because the interpolation point is a parenthesized SQL expression list rather than an identifier-only position, a supplied element may carry arbitrary expressions, including correlated subqueries. An application that forwards a client-controlled value into distinctOn, for instance to let a caller choose a deduplication column, allows that client to read data anywhere the application's database role can reach through boolean or time-based inference, independently of the entity being queried. validateOrderByCondition, the allowlist check guarding the orderBy family in the same class, is not applied to this path.

Summary

SQL Injection vulnerability in TypeORM before 0.3.26 via crafted request to repository.save or repository.update due to the sqlstring call using stringifyObjects default to false.

Details

Vulnerable Code:

js const { username, city, name} = req.body; const updateData = { username, city, name, id:userId }; // Developer aims to only allow above three fields to be updated const result = await userRepo.save(updateData);

Intended Payload (non-malicious):

username=myusername&city=Riga&name=Javad

OR

{username:\"myusername\",phone:12345,name:\"Javad\"}

SQL query produced:

sql UPDATE user SET username = 'myusername', city = 'Riga', name = 'Javad' WHERE id IN (1);

Malicious Payload:

username=myusername&city[name]=Riga&city[role]=admin

OR

{username:\"myusername\",city:{name:\"Javad\",role:\"admin\"}}

SQL query produced with Injected Column:

sql UPDATE user SET username = 'myusername', city = name = 'Javad', role = 'admin' WHERE id IN (1);

Above query is valid as city = name = Javad is a boolean expression resulting in city = 1 (false). “role” column is injected and updated.

Underlying issue was due to TypeORM using mysql2 without specifying a value for the stringifyObjects option. In both mysql and mysql2 this option defaults to false. This option is then passed into SQLString library as false. This results in sqlstring parsing objects in a strange way using objectToValues.

DISPUTED The findOne function in TypeORM before 0.3.0 can either be supplied with a string or a FindOneOptions object. When input to the function is a user-controlled parsed JSON object, supplying a crafted FindOneOptions instead of an id string leads to SQL injection. NOTE: the vendor's position is that the user's application is responsible for input validation.

Prototype pollution vulnerability in the TypeORM package < 0.2.25 may allow attackers to add or modify Object properties leading to further denial of service or SQL injection attacks.