Vulnerability: loopback-connector-postgresql Vulnerable to Improper Sanitization of `contains` Filter Improper input validation on the `contains` LoopBack filter may allow for arbitrary SQL injection.

### Impact

When the extended filter property `contains` is permitted to be interpreted by the Postgres connector, it is possible to inject arbitrary SQL which may affect the confidentiality and integrity of data stored on the connected database.

This affects users who does any of the following:

- Connect to the database via the DataSource with `allowExtendedProperties: true` setting OR
- Uses the connector's CRUD methods directly OR
- Uses the connector's other methods to interpret the LoopBack filter.

### Patches

Patch release `loopback-connector-postgresql@5.5.1` has been published of which resolves this issue.

### Workarounds

Users who are unable to upgrade should do the following if applicable:

- Remove `allowExtendedProperties: true` DataSource setting
- Add `allowExtendedProperties: false` DataSource setting
- When passing directly to the connector functions, manually sanitize the user input for the `contains` LoopBack filter beforehand.
Vulnerability ID: GHSA-j259-6c58-9m58
CWE: CWE-20
Severity score: 9.3
Project: https://github.com/loopbackio/loopback-connector-postgresql
Published: 2022-08-11
File: lib/postgresql.js
Commit message: fix: improve filter sanitisation

Add sanitisation of user-input for `contains` LoopBack filter which may allow for arbitrary SQL injection.

Signed-off-by: Rifa Achrinza <25147899+achrinza@users.noreply.github.com>
Commit author: Rifa Achrinza

Vulnerable version (before fix):
 PostgreSQL.prototype.buildExpression = function(columnName, operator,       return new ParameterizedSQL(columnName + regexOperator,         [operatorValue.source]);     case 'contains':       return new ParameterizedSQL(columnName + ' @> array[' + operatorValue.map((v) => `'${v}'`) + ']::'         + propertyDefinition.postgresql.dataType);     case 'match':       return new ParameterizedSQL(`to_tsvector(${columnName}) @@ to_tsquery('${operatorValue}')`);     default:       // invoke the base implementation of `buildExpression`       return this.invokeSuper('buildExpression', columnName, operator,

Fixed version (after fix):
 PostgreSQL.prototype.buildExpression = function(columnName, operator,       return new ParameterizedSQL(columnName + regexOperator,         [operatorValue.source]);     case 'contains':       return new ParameterizedSQL(columnName + ' @> array[' + operatorValue.map(() => '?') + ']::'         + propertyDefinition.postgresql.dataType,         operatorValue);     case 'match':       return new ParameterizedSQL(`to_tsvector(${columnName}) @@ to_tsquery(?)`, [operatorValue]);     default:       // invoke the base implementation of `buildExpression`       return this.invokeSuper('buildExpression', columnName, operator,

Patch:
patch: @@ -545,10 +545,11 @@ PostgreSQL.prototype.buildExpression = function(columnName, operator,
       return new ParameterizedSQL(columnName + regexOperator,
         [operatorValue.source]);
     case 'contains':
-      return new ParameterizedSQL(columnName + ' @> array[' + operatorValue.map((v) => `'${v}'`) + ']::'
-        + propertyDefinition.postgresql.dataType);
+      return new ParameterizedSQL(columnName + ' @> array[' + operatorValue.map(() => '?') + ']::'
+        + propertyDefinition.postgresql.dataType,
+        operatorValue);
     case 'match':
-      return new ParameterizedSQL(`to_tsvector(${columnName}) @@ to_tsquery('${operatorValue}')`);
+      return new ParameterizedSQL(`to_tsvector(${columnName}) @@ to_tsquery(?)`, [operatorValue]);
     default:
       // invoke the base implementation of `buildExpression`
       return this.invokeSuper('buildExpression', columnName, operator,
path: lib/postgresql.js