Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.34 and 9.6.0-alpha.8, the email verification endpoint (/verificationEmailRequest) returns distinct error responses depending on whether an email address belongs to an existing user, is already verified, or does not exist. An attacker can send requests with different email addresses and observe the error codes to determine which email addresses are registered in the application.
This is a user enumeration vulnerability that affects any Parse Server deployment with email verification enabled (verifyUserEmails: true). This vulnerability is fixed in 8.6.34 and 9.6.0-alpha.8.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://github.com/parse-community/parse-server/releases/tag/8.6.34
security-advisories@github.com
https://github.com/parse-community/parse-server/releases/tag/9.6.0-alpha.8
security-advisories@github.com
https://github.com/parse-community/parse-server/security/advisories/GHSA-w54v-h…
security-advisories@github.com