Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.9. and 8.6.22, the OAuth2 authentication adapter, when configured without the useridField option, only verifies that a token is active via the provider's token introspection endpoint, but does not verify that the token belongs to the user identified by authData.id. An attacker with any valid OAuth2 token from the same provider can authenticate as any other user.
This affects any Parse Server deployment that uses the generic OAuth2 authentication adapter (configured with oauth2: true) without setting the useridField option. This vulnerability is fixed in 9.5.2-alpha.9. and 8.6.22.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://github.com/parse-community/parse-server/releases/tag/8.6.22
security-advisories@github.com
https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.9
security-advisories@github.com
https://github.com/parse-community/parse-server/security/advisories/GHSA-fr88-w…
security-advisories@github.com