CVE-2021-39138
Published: 19 August 2021
Summary
CVE-2021-39138 is a medium-severity Improper Authentication (CWE-287) vulnerability in Parseplatform Parse-Server. Its CVSS base score is 4.8 (Medium).
Operationally, ranked at the 44.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-1504
Vulnerability details
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Developers can use the REST API to signup users and also allow users to login anonymously. Prior to version 4.5.1, when an…
more
anonymous user is first signed up using REST, the server creates session incorrectly. Particularly, the `authProvider` field in `_Session` class under `createdWith` shows the user logged in creating a password. If a developer later depends on the `createdWith` field to provide a different level of access between a password user and anonymous user, the server incorrectly classified the session type as being created with a `password`. The server does not currently use `createdWith` to make decisions about internal functions, so if a developer is not using `createdWith` directly, they are not affected. The vulnerability only affects users who depend on `createdWith` by using it directly. The issue is patched in Parse Server version 4.5.1. As a workaround, do not use the `createdWith` Session field to make decisions if one allows anonymous login.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Session content review can reveal authentication bypasses or failures in session establishment.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
Identity providers centralize and enforce authentication mechanisms, reducing improper authentication.
Enforces correct authorization checks during the identifier assignment process.
Personnel screening, identity verification, and access-agreement requirements support reliable authentication and reduce authentication bypass opportunities.
Decoy authentication surfaces detect bypass attempts and deflect real credential attacks through observable malicious interactions.
Periodic review and update of procedures reduces incorrect authorization implementations over time.
Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.