{"cve":"CVE-2021-39138","nvd":{"published":"2021-08-19T16:15:12.483","modified":"2026-06-17T04:03:08.527","status":"Modified","description":"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 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":6.5},"cwes":["CWE-863","CWE-287"],"references":["https://github.com/parse-community/parse-server/commit/147bd9a3dc43391e92c36e05d5db860b04ca27db","https://github.com/parse-community/parse-server/releases/tag/4.5.1","https://github.com/parse-community/parse-server/security/advisories/GHSA-23r4-5mxp-c7g5","https://github.com/parse-community/parse-server/commit/147bd9a3dc43391e92c36e05d5db860b04ca27db","https://github.com/parse-community/parse-server/releases/tag/4.5.1"],"products":["parseplatform:parse-server"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-39138","score":0.00993,"percentile":0.62628,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-23r4-5mxp-c7g5","url":"https://osv.dev/vulnerability/GHSA-23r4-5mxp-c7g5","summary":"parse-server new anonymous user session acts as if it's created with password","modified":"2026-07-08T06:29:03.167430438Z","packages":[{"ecosystem":"npm","name":"parse-server","purl":"pkg:npm/parse-server","ranges":["<4.5.2"],"fixed":["4.5.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}