{"cve":"CVE-2021-37705","nvd":{"published":"2021-08-13T21:15:06.973","modified":"2026-06-17T04:01:01.420","status":"Modified","description":"OneFuzz is an open source self-hosted Fuzzing-As-A-Service platform. Starting with OneFuzz 2.12.0 or greater, an incomplete authorization check allows an authenticated user from any Azure Active Directory tenant to make authorized API calls to a vulnerable OneFuzz instance. To be vulnerable, a OneFuzz deployment must be both version 2.12.0 or greater and deployed with the non-default --multi_tenant_domain option. This can result in read/write access to private data such as software vulnerability and crash information, security testing tools and proprietary code and symbols. Via authorized API calls, this also enables tampering with existing data and unauthorized code execution on Azure compute resources. This issue is resolved starting in release 2.31.0, via the addition of application-level check of the bearer token's `issuer` against an administrator-configured allowlist. As a workaround users can restrict access to the tenant of a deployed OneFuzz instance < 2.31.0 by redeploying in the default configuration, which omits the `--multi_tenant_domain` option.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","score":10.0},"cwes":["CWE-863","CWE-285","CWE-346"],"references":["https://github.com/microsoft/onefuzz/commit/2fcb4998887959b4fa11894a068d689189742cb1","https://github.com/microsoft/onefuzz/pull/1153","https://github.com/microsoft/onefuzz/releases/tag/2.31.0","https://github.com/microsoft/onefuzz/security/advisories/GHSA-q5vh-6whw-x745","https://pypi.org/project/onefuzz/"],"products":["microsoft:onefuzz"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-37705","score":0.02415,"percentile":0.84143,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-q5vh-6whw-x745","url":"https://osv.dev/vulnerability/GHSA-q5vh-6whw-x745","summary":"Improper Authorization and Origin Validation Error in OneFuzz","modified":"2026-07-08T06:29:53.314609918Z","packages":[{"ecosystem":"PyPI","name":"onefuzz","purl":"pkg:pypi/onefuzz","ranges":[">=2.12.0 <2.31.0"],"fixed":["2.31.0"]}]},{"id":"PYSEC-2021-344","url":"https://osv.dev/vulnerability/PYSEC-2021-344","summary":"","modified":"2023-11-08T04:06:23.491489Z","packages":[{"ecosystem":"PyPI","name":"onefuzz","purl":"pkg:pypi/onefuzz","ranges":[">=2.12.0 <2.31.0"],"fixed":["2.31.0"]}]}],"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."]}