CVE-2022-35942 is a medium-severity SQL injection vulnerability affecting the loopback-connector-postgresql component of the LoopBack framework, versions prior to 5.5.1. The vulnerability arises due to improper neutralization of special elements in SQL commands (CWE-89) when processing the extended LoopBack filter property `contains`. Specifically, when the `contains` filter is allowed to be interpreted by the PostgreSQL connector—enabled via the `allowExtendedProperties: true` DataSource setting or when using the connector's CRUD or other methods directly—malicious input can be injected into the SQL query. This injection can lead to arbitrary SQL execution against the connected PostgreSQL database, potentially compromising the confidentiality and integrity of the stored data. The vulnerability is rooted in insufficient input validation and sanitization of user-supplied data passed through the `contains` filter, allowing attackers to craft payloads that alter the intended SQL commands. A patch addressing this issue was released in version 5.5.1 of the connector. For users unable to upgrade, mitigation includes disabling the `allowExtendedProperties` setting by setting it to false and manually sanitizing inputs passed to connector functions that interpret the `contains` filter. No known exploits have been reported in the wild to date, but the vulnerability presents a significant risk due to the potential for data leakage or unauthorized data manipulation via SQL injection.

For European organizations utilizing the LoopBack framework with the loopback-connector-postgresql prior to version 5.5.1, this vulnerability poses a risk of unauthorized data access and modification. Successful exploitation could lead to exposure of sensitive personal data, intellectual property, or critical business information, violating GDPR and other data protection regulations. The integrity of database records could be compromised, leading to data corruption or fraudulent transactions. Availability impacts are less direct but could occur if injected SQL commands disrupt database operations. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often rely on PostgreSQL databases and LoopBack for backend services, are particularly at risk. The vulnerability's exploitation does not require authentication if the application exposes the vulnerable API endpoints publicly, increasing the attack surface. Given the potential for data breaches, affected organizations may face regulatory penalties, reputational damage, and operational disruptions.

1. Upgrade the loopback-connector-postgresql package to version 5.5.1 or later to apply the official patch. 2. If immediate upgrade is not feasible, explicitly set the DataSource configuration parameter `allowExtendedProperties` to false to disable interpretation of extended filter properties like `contains`. 3. Implement rigorous input validation and sanitization for all user inputs that may be passed to the `contains` filter or directly to connector methods, ensuring that special SQL characters and patterns are neutralized or escaped. 4. Conduct code reviews and security testing focused on API endpoints that utilize LoopBack filters, especially those exposing the `contains` filter functionality. 5. Employ Web Application Firewalls (WAFs) with rules targeting SQL injection patterns specific to PostgreSQL syntax to provide an additional layer of defense. 6. Monitor database query logs for anomalous or unexpected SQL commands that could indicate attempted exploitation. 7. Educate development teams about secure coding practices related to dynamic query construction and the risks of enabling extended filter properties without proper safeguards.