GHSA-655c-2xf3-77x9: Parse Server before 8.6.111 and 9.0.0 before 9.10.6-alpha.3 Field Corruption via Null Dot Notation Key
Parse Server before 8.6.111 and 9.0.0 before 9.10.6-alpha.3 on MongoDB skips field type validation for null-valued dot notation keys, allowing sub-documents to be written beneath Pointer, Number, String, Date, or Boolean fields. Any client with write access, including unauthenticated clients where public writes are permitted, can corrupt field values, make objects unreadable via internal date fields, or break atomic operations on number fields.
Event History
Frequently Asked Questions
Which deployments are exposed?
Parse Server deployments using MongoDB are affected if they run a version before 8.6.111, or a 9.0.0 through 9.10.6-alpha.2 release. Exposure requires that a client can write to the affected class and field.
Does exploitation require authentication or special privileges?
No authentication is inherently required. Any client with write access can exploit the issue, including unauthenticated clients when public writes are enabled.
What conditions make exploitation possible?
An attacker needs the ability to submit a write using a null-valued dot-notation key targeting a field expected to hold a Pointer, Number, String, Date, or Boolean value. The vulnerable validation behavior then permits a sub-document to be written under that field.
What can happen if a vulnerable field is modified?
Field values can be corrupted by writing sub-documents beneath scalar or Pointer fields. Objects may become unreadable when internal date fields are affected, and atomic operations can fail on number fields.
What can be done while patching is pending?
Restrict write access to affected classes and fields, particularly by disabling public writes where they are permitted. This reduces the set of clients able to submit the malicious write payloads.