CVE-2021-37705Critical· 10.0▾ MidnightImproper Authorization and Origin Validation Error in OneFuzz
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 55 · likelihood 0.5 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
2.4%
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:
--multi_tenant_domain optionThis can result in read/write access to private data such as:
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.
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.
You can find an overview of the Microsoft Identity Platform here. This vulnerability applies to the multi-tenant application pattern, as described here.
If you have any questions or comments about this advisory:
onefuzz >= 2.12.0, < 2.31.0Upgrade to a patched release:
onefuzz 2.31.0