Parse Server Authentication and Injection Flaws

### Impact An attacker can exploit LiveQuery subscriptions to infer the values of protected fields without directly receiving them. By subscribing with a WHERE clause that references a protected field (including via dot-notation or `$regex`), the attacker can observe whether LiveQuery events are delivered for matching objects. This creates a boolean oracle that leaks protected field values. The attack affects any class that has both `protectedFields` configured in Class-Level Permissions and LiveQuery enabled. ### Patches The fix adds validation of the LiveQuery subscription WHERE clause against the class's protected fields, mirroring the existing REST API validation. If a subscription's WHERE clause references a protected field directly, via dot-notation, or inside `$or` / `$and` / `$nor` operators, the subscription is rejected with a permission error. This is applied during subscription creation, so existing event delivery paths are not affected. ### Workarounds Disable LiveQuery for classes that use `protectedFields` in their Class-Level Permissions, or remove `protectedFields` from classes that require LiveQuery. ### References - GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-j7mm-f4rv-6q6q - Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.9 - Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.35

Parse Server versions before 8.6.34 and 9.6.0-alpha.8 leak user registration status through differential error responses on the email verification endpoint, enabling attackers to enumerate valid email addresses in the system when email verification is enabled. Deployments with verifyUserEmails set to true are vulnerable to this user enumeration attack, which allows an attacker to systematically identify registered accounts by analyzing response codes from the /verificationEmailRequest endpoint. No patch is currently available for affected installations.

### Impact An attacker with access to the master key can inject malicious SQL via crafted field names used in query constraints when Parse Server is configured with PostgreSQL as the database. The field name in a `$regex` query operator is passed to PostgreSQL using unparameterized string interpolation, allowing the attacker to manipulate the SQL query. While the master key controls what can be done through the Parse Server abstraction layer, this SQL injection bypasses Parse Server entirely and operates at the database level. This vulnerability only affects Parse Server deployments using PostgreSQL. ### Patches The fix applies proper SQL identifier escaping to field names in the query handler and hardens query field name validation to reject malicious field names for all query types. ### Workarounds There is no known workaround. ### References - GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-c442-97qw-j6c6 - Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.10 - Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.36